Oh well, it was just a thought! Would have been convenient, as they're not a million miles from me. Thanks for your reply, anyway - better late than never, I say.
Walking boot repairers used to exist, I had a pair resoled some time in the 1980s by a bootmaker called James Taylor, I think, in the Marylebone area, and there used to be a specialist company somewhere in the north of England who had a half-page advert in TGO each month.
I'll think about it again when my boots have become even more worn, and maybe then I'll do a Net search, but to be honest I'm not sure it would be worth it with today's labour charges. The money would probably be better put towards a new pair of boots.