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.

Papurau'r Parch. William Williams a'i wraig Myfi Williams. Maent yn cynnwys dyddiaduron y Parch. William Williams,1936-1944,1971-1984; papurau, 1937-1942, yn dyddio o'i gyfnod yn yr ysgol a'r coleg; nodiadau darlithoedd; nodiadau ymchwil ar hanes Capel Maengwyn, Machynlleth, ac achos y Methodistiaid yn sir Drefaldwyn; pregethau etc.; a cherddi a storïau a gyfansoddwyd gan y Parch. William David Davies. Ceir hefyd pedwar llyfr nodiadau gan gynnwys drafftiau, 1973, o nofel arfaethedig gan y Parch. William Williams ar y Parch. John Elias (1774-1841). Mae papurau Myfi Williams yn cynnwys llyfrau nodiadau a ffeiliau o nodiadau ar hanes lleol; cyfansoddiadau a gyflwynwyd mewn gwahanol gystadlaethau eisteddfodol, 1958-1976; sgriptiau radio,1961-1967 etc. Ceir hefyd lythyrau a chardiau, c. 1961-1980, a anfonwyd at Gwilym a Myfi Williams = Papers of the Rev. William Williams and his wife Myfi Williams. They include the diaries of the Rev. William Williams, 1936-1944, 1971-1984; papers, 1937-1942, dating from his schooldays and college days; lecture notes; research notes on the history of Maengwyn chapel, Machynlleth, and the Methodist cause in Montgomeryshire; sermons etc.; and poems and stories written by Rev. William David Davies. There are also four notebooks including drafts, 1973, of an intended novel by Rev. William Williams on Rev. John Elias (1774-1841). The papers of Mrs Myfi Williams include notebooks and files of notes on local history; compositions submitted for various eisteddfod competitions, 1958-1976; radio scripts, 1961-1967 etc. There are also letters and cards. 1961-1908, addressed to Gwilym and Myfi Williams.