Jeff,
No car? …. No problem!
As far as services go, you are probably right in that there tend to be fewer people servicing Tractions but those you named are generally still around.
John Gillard did temporarily cease advertising in FP while he is undergoing relocation from the Old Kent Road to further out to the east of London so he is probably not in the best position (or location) to help you at present.
I guess the Devon chap would be Mark Harding – he is still operating – mark.harding616@btinternet.com
Further afield from you there is Darrin Brownhill (Citroen Classics) in West London and James Geddes (Traction Repairs) in the far flung reaches of Northumberland – both advertise in FP.
As for which area you come under, there are no hard and fast boundaries so it is what suits you. I suppose you could probably go for the South West (Howard Spiers) or West of England( Terence McAuley) or, thinking outside the box, …… how about starting a new group in your area …?
b………….