Papers of the Williams family of Bontdolgadfan, including deeds for property in Bontdolgadfan, 1731-1877 (these remain uncatalogued); Bontdolgadfan Calvinistic Methodist chapel baptism register, 1812-1864, records of Bontdolgadfan Welsh and English chapels, Machynlleth, 1867-1877; papers relating to eisteddfodau at Bontdolgadfan, Llanbrynmair and Machynlleth, 1870-1923; account and memorandum books relating to the Post Office, Bontdolgadfan, 1884-1902; records of the Llanbrynmair Agricultural School Library, 1845-1847; balance sheets of the [Llanbrynmair] Friendly Society, 1858-1876; family correspondence, school exercise books and personal papers of the Williams, Griffiths and Roberts families, 1836-1922, journal or autobiography of the Rev. Richard Williams, 1802-1842; records of the overseers of the poor for Llanbrynmair, 1744-1876; records of Maglona Lodge of Good Templars, Machynlleth and other societies, 1863-1877; sermon notes, 1816-1917; and diary of Richard Tibbott, 1741-1742.

Records, 1837-1955, of former local government bodies of Machynlleth, Montgomeryshire, and neighbouring parts of Merionethshire, comprising minute books, letter books, ledgers, account books, reports, valuations, registers and rate books of the Machynlleth Poor Law Union, 1837-1930, minute books, letter books, ledgers, account books, reports, valuations, registers and rate books of the Machynlleth Rural District Council, 1892-1957, a letter book and rate account books of the Mallwyd Urban District Council, 1922-1930, and minute books, account books, registers and other records of the Machynlleth and Estimaner (Ystumanner) Petty Sessions, 1853-1953, together with miscellaneous administrative, financial and personal papers, 1837-1931, from the offices of Henry Evans relating to clients, local government, local businesses, and other solicitors who practised in and around Machynlleth.

Papers relating to Richard Rees ('Maldwyn', 1851-1927), of Machynlleth, Montgomeryshire, and Edward Walter Rees, ('Gwallter Dyfi', 1881-1940), of Carmarthen, including correspondence, 1874-1940; printed materials, 1866-1937; papers relating to the National Eisteddfod and the Gorsedd of Bards, 1909-1939; papers relating to the National Petition on the Legal Status of the Welsh Language, 1938-1939; papers relating to Maengwyn Calvinistic Methodist Chapel, Machynlleth, 1875-1920; and various papers relating to manifold aspects of Machynlleth life.

Machynlleth Salvage Papers, 1858-1925, including correspondence from Machynlleth Urban District Council clerks' office, 1895-1923; rate books, 1861-1886; Poor Law rate books, Machynlleth parish, 1916-1917; Machynlleth Poor Law Union overseer's book of receipts and payments, 1910-1927; papers relating to the local government elections, 1894-1908; Machynlleth Waterworks papers, 1878-1910; Dovey fishery papers, 1890-1902; papers relating to Royal visits, 1889-1911; papers relating to roads and streets, 1898-1911; Machynlleth sewerage schemes papers, 1897-1914; papers relating to Machynlleth town hall, 1862-1891; papers relating to Machynlleth markets and fairs, 1903-1916; papers relating to the fire brigade, 1909-1914; papers relating to Machynlleth isolation hospital, 1912-1913; and papers relating to the Owain Glyndwr Institute, 1910-1925.