Development Board for Rural Wales records, containing minutes and other papers of the Board and various committees, 1977-1994; general administrative files concerning the establishment of the Board, its functions and responsibilities, and correspondence with other organizations, 1966-1990; construction files containing correspondence, contracts and estate plans relating to housing and industrial developments executed by the Board, particularly in Newtown, 1968-1993; records such as correspondence, minutes, notes and other papers relating to research studies on economic and social life in Mid-Wales carried out by the Board, 1968-1995; files relating to the Board's marketing and promotional strategy, 1978-1991; and press releases, 1977-1990; Mid-Wales Development Corporation records, 1962-1979, including annual reports, 1969-1977, minutes and papers of the Board and various committees, 1968-1979, and seal registers relating to MWDC projects, 1968-1976, containing compulsory purchase orders, contracts, leases and other documents.

An additional three files relating to the Development Board for Rural Wales, being DB/CF/101/1; DB/CF/101/2; DB/CF/101/3 – (Extension to Goodall & Swanwick factories at Dolgellau; factories at Dolgellau; and extension to Marian Park Industrial Estate, Dolgellau). These remain uncatalogued, and are closed for ten years from the date of the latest document in each file.

Press letter books, 1878-1920, press invoice books, 1878-1919, account books, 1893-1920, and a minute book, 1900-1901.

Deeds, 1490-1977, including deeds and documents mainly relating to properties on Anglesey, Caernarfonshire, Merionethshire and Middlesex, 1675-1977; and deeds relating to properties in Finchley, Middlesex, 1490-1796.

Traethawd 'Golwg ar hanes ardal Llawrybetws neu Nantffreuer: o Bethel i lawr i Gaefaes' a ysgrifennodd D. Tecwyn Lloyd ar hanes lleol bro ei febyd, 'o gof personol ac amryfal gofnodion', gan ganolbwyntio ar anheddau'r ardal.

Papurau Bob Owen yn cynnwys traethodau eisteddfodol, 1910-1941; beirniadaethau ar draethodau eisteddfodol, 1916-1949; crynodebau o bregethau a glywodd, 1895-1927; teipysgrifau rhaglenni radio yr oedd ynghlwm wrthynt, 1936-1957; gohebiaeth, 1908-1961, yn cynnwys llythyrau Dr Thomas Richards, 1923-1960; dyddiaduron, 1905-1961; papurau personol, 1898-1961; papurau teuluol, 1900-1923; copïau a drafftiau o ddarlithoedd, erthyglau a thraethodau, 1906-1950; nodiadau ac adysgrifau helaeth ganddo o farddoniaeth Gymraeg, ewyllysiau a mynegeion ewyllysiau, cartiau achau ac achresi, cofrestri plwyf ac adysgrifau'r esgob, dyddiaduron, llythyrau, almanaciau, cofnodion llys, yn ymwneud yn bennaf â siroedd Caernarfon a Meirionnydd, a chofiannau, [20 gan., ½ cyntaf]; nodiadau ar anghydffurfiaeth yng Ngogledd Cymru, plwyfi siroedd Meirionnydd a Chaernarfon, llongau a morwyr o Gymru a Chymry Llundain, [20 gan., ½ cyntaf]; nodiadau pwysig ar ymfudo o Gymru, yn enwedig i'r Unol Daleithiau, [20 gan., ½ cyntaf]; copïau teipysgrif o gofnodion corfforaethau yn cynnwys Parc Cenedlaethol Eryri a Chyngor Sir Feirionnydd, 1922-1962; cofnodion gwreiddiol a ddaeth i feddiant Bob Owen, yn bennaf cofnodion Chwarel Parc a Chroesor, sir Feirionnydd, yn cynnwys cyfrifon a chofnodion, 1891-1941, a chofnodion ysgolion ac ysgolion Sul, 1861-1957; a thorion ac adysgrifau o amrywiol gyfnodolion Cymreig, 1816-1965. = Papers of Bob Owen including eisteddfod essays, 1910-1941; adjudications of eisteddfod essays, 1916-1949; summaries of sermons heard by him, 1895-1927; typescripts of radio programmes involving him, 1936-1957; correspondence, 1908-1961, including letters from Dr Thomas Richards, 1923-1960; diaries, 1905-1961; personal papers, 1898-1961; family papers, 1900-1923; copies and drafts of lectures, articles and monographs, 1906-1950; extensive notes and transcripts by Bob Owen of Welsh poetry, wills and indexes of wills, pedigrees and genealogies, parish registers and bishops' transcripts, diaries, letters, almanacs, court records, mainly relating to Caernarfonshire and Merionethshire, and biographies, [20 cent, first ½]; notes on nonconformists in North Wales, Merionethshire and Caernarvonshire parishes, Welsh ships and sailors and the London Welsh, [20 cent, first ½]; important notes on emigration from Wales, especially to the United States, [20 cent, first ½]; typescript records of bodies including Snowdonia National Park and Merioneth County Council, 1922-1962; original records acquired by Bob Owen, mainly records of Parc and Croesor Quarry, Merionethshire, including accounts and minutes, 1891-1941, and school and Sunday School records, 1861-1957; and cuttings and transcripts from various Welsh periodicals, 1816-1965.

Gohebiaeth, barddoniaeth, rhyddiaith a phapurau teuluol, yn ymwneud â J. W. Jones, 1878-1954, a'i dad, 'Glan Barlwyd', 1866-1917; deunydd a gasglwyd gan J. W. Jones yn ymnweud ag unigolion a sefydliadau yn ardal Blaenau Ffestiniog, gan gynnwys gohebiaeth, barddoniaeth a phapurau eraill o eiddo 'Gwilym Deudraeth', 1917-1939, 'Elfyn', 1874-1917, Y Parch. R. R. Morris, 1883-1933, 'Alafon', 1875-1915, 'Llifon', 1899-1916, 'Isallt', 1887-1913, a 'Glyn Myfyr', 1893-1937; llythyrau at John Daniel Davies yn rhinwedd ei swydd fel golygydd Y Rhedegydd, 1930-1942; barddoniaeth a phapurau eraill o eiddo T. Gwynn Jones, 1910-1944; barddoniaeth, [1840]-1940, gan amryw feirdd, yn cynnwys Hedd Wyn ac R. Williams Parry; deunydd rhyddiaith amrywiol, peth ohono wedi'i gyhoeddi yn Y Drysorfa ac yn Y Rhedegydd, 1879-1954; llawysgrifau cerddorol, 1876-[c. 1934]; beirniadaethau eisteddfodol, 1870-1939; llyfrau lloffion yn cynnwys torion o'r wasg, [c. 1879]-1940; dyddiaduron, 1864-1935; cofnodion chwareli llechi Blaenau Ffestiniog, 1868-1951; amryw gyfrifon a llyfrau cyfrifon yn ymwneud â gwahanol fusnesau a sefydliadau, 1784-1932; cofnodion yn ymwneud ag eglwysi'r Methodistiaid Calfinaidd, 1840-1951, gan gynnwys rhai Bethel, Tanygrisiau, [1840x1945]; pregethau a nodiadau crefyddol,1846-1952; deunydd printiedig yn cynnwys effemera etholiadol, marwnadau, baledi, carolau ac emynau, 1820-1948; a gweithredoedd a dogfennau yn ymwneud â siroedd Caernarfon, Meirionnydd a Dinbych, 1759-1947. = Correspondence, poetry, prose and family papers, relating to J. W. Jones, 1878-1954, and to his father, 'Glan Barlwyd', 1866-1917; material collected by J. W. Jones relating to individuals and organizations in the Blaenau Ffestiniog area, including correspondence, poetry and other papers of 'Gwilym Deudraeth', 1917-1939, 'Elfyn', 1874-1917, Rev. R. R. Morris, 1883-1933, 'Alafon', 1875-1915, 'Llifon', 1899-1916, 'Isallt', 1887-1913, and 'Glyn Myfyr', 1893-1937; letters to John Daniel Davies as editor of Y Rhedegydd, 1930-1942; poetry and other papers of T. Gwynn Jones, 1910-1944; poetry, [1840]-1940, by various poets, including Hedd Wyn and R. Williams Parry; various prose material, some of which was published in Y Drysorfa and Y Rhedegydd, 1879-1954; musical manuscripts, 1876-[c. 1934]; eisteddfod adjudications, 1870-1939; scrapbooks containing press cuttings, [c. 1879]-1940; diaries, 1864-1935; records of Blaenau Ffestiniog slate quarries, 1868-1951; various accounts and account books relating to various trades and organisations, 1784-1932; records relating to Calvinistic Methodist churches, 1840-1951, including those of Bethel, Tanygrisiau, [1840x1945]; sermons and religious notes, 1846-1952; printed material including electoral ephemera, elegies, ballads, carols and hymns, 1820-1948; and deeds and documents relating to Caernarfonshire, Merionethshire and Denbighshire, 1759-1947.

Papurau Arthur Cadnant Ellis [20fed ganrif], yn cynnwys traethodau ar 'Rhai o Enwogion Aberllefenni' a 'John Jones (Jac) Glan-y-gors a'i Amserau (1766-1821)'; braslun o hanes achos y Methodistiaid Calfinaidd yn Harlech a Llanfair, sir Feirionnydd; torion erthyglau, llythyrau, etc., a gyfrannodd i'r wasg; a nodiadau amrywiol = Papers of Arthur Cadnant Ellis, [20th century], including essays on 'Rhai o Enwogion Aberllefenni' and 'John Jones (Jac) Glan-y-gors a'i Amserau (1766-1821)'; a brief history of the Calvinistic Methodist cause in Harlech and Llanfair, Merionethshire; cuttings of articles, letters, etc., which he contributed to the press; and miscellaneous notes.