One of the classics in London is the adding of an additional 'i' to Upminster and Westminster. When I used to travel regularly to Hammersmith station in the days before recorded announcements, the announcers would often say 'Upminister' and 'Westminister', and in a variety of accents, including Irish, Indian, West Indian and London.
Moving away a bit from the railway, an East London woman I once worked with always called Saint Botolph church 'Saint Bolotov', perhaps mixing up the Christian saint with the Soviet foreign minister of her youth.
--- old post above --- --- new post below ---
How's the town pronounced? Windum?
Spot on! Quite a few names in East Anglia are officially contracted, that is, how the BBC would normally pronounce it, Wymondham being an example. Others are colloquially contracted; my granny's neighbours near Lowestoft always pronounced Norwich as 'Narge'.
Whether Hunstanton is officially or colloquially contracted to 'Hunston' I don't know. On a delightful short film, John Betjeman travelled from King's Lynn on a DMU, saying that the train would be going to Snettersham, 'pronounced "Snetsam"'. Neither town has any rail service these days.
I read somewhere that the Ordnance Survey put the second 'h' in Haverhill when they were mapping the area because they thought that the inhabitants were missing it out when saying the name; whether this is true I don't know.
Wraysbury in Middlesex is now the official rendering of Wyrardisbury, and is how it's always been pronounced; the station on the former London and South-Western line to Windsor originally had the old spelling, but had changed before 1900 to the new one.
