There is evidence that the t of Saint was similarly prefixed to Olave at St Olave's Bridge, Southwark, Chichester, Bradford-on-Avon, Chester, Dublin and North Widewall (Orkney)... Useful parallels are the form St Twosole recorded by John Aubrey (Remaines of Gentilisme and Judaisme, p. 29) as the Wiltshire country folk's rendering of S. Oswald; the pronunciation [tu 'zi] for St Osyth, in the seventeenth-century Seinte Toosie (PN Essex 348); T'andry cakes, made in Bucks on the feast of S. Andrew (W. Henderson, Notes on the Folk-Lore of the Northern Counties, 2nd ed., p. 98); tawdry, originally applied to laces (neckties) bought at St Audrey's Fair at Ely; Tan Gate (PN. Wilts 22), which was Seynt Anne Gate in 1455.
Bruce Dickins, ‘The Cult of S. Olave in the British Isles’, Saga-book of the Viking Society XII (1937-45), 53-80 (61, n.4).
I knew that 'tawdry' came from St Audrey (itself a corruption of St Æthelthryth) but the others are new to me.
See also Tooley St, London...