OldNicKilby - I bow to your orthography of Shipbourne - mine was only an attempt at something with the r not very much apparent at all.

Steve Gardam, I was told about Eboracum by a member of the English Place Names Society who had studied under John Dodgson, the doyen of such matters. I couldn't remember the exact details, but it, I now think, involved the dropping of the ending, not as far as the present bishopric, but as far as Eborac. This was interpreted and mangled by the Anglian settlers as Eoforwic, or boar-place, which would have given an initial Y sound, with the central r and the final c sound, which was subsequently re-interpreted and mangled by the Vikings who formed Jorvik, which, as you say, slides into modern York. The intermediate forms exist in writing. See https://en.wikipedia.org/wiki/York

Can't get into the clickymaker and have forgotten how to do it manually.

And I can't feel much difference in the mouth between idge and itch, just in the voicing, and what I hear around Greenwich is less voiced. It may even be the difference between what men say and women say.

Will, my mind passed over Bozzum, and decided to leave it to someone else.

Mr Red, Strood, Kent, is spelled Strood, so no problem.

And I've remembered the place in Sussex signed as Terrible Down, with a tale of the cutting down of brave Saxons by the Normans in 1066, but which is said Turbledown, and etymologically can be shown to originate from a four letter word beginning with t and rhyming with word.

Penny