Thanks Mike, rthomas and Tony for those last couple of comments.
I went along to that shop I mentioned in the OP yesterday. The guy had a lot of old cameras but I have to say most were in pretty poor shape. Still, he's a collector only and has a man down the road who specialises in refurbishing them.
First thing I noticed was the Yashica Electro 35 GSN is way too big! I did tell you I was a newbie but I was surprised at how big this thing is. I need something for street photography and if I went for this I may as well cart around my 5Dii.
He had a Electro 35 GX, which was more compact and felt much better. It was still not in great shape though. Although a lot of the grubbiness could be cleaned up the thing that bothered me most was the 'runner' bit that the film presses against (not the back plate, the strip above and below the lens hole) might scratch the film due to a little bit of corrosion. Not sure if the repair man can fix this or not. Also the viewfinder was misty. I imagine the only way of replacing this would be to replace the plastic or glass with new bits, but is this easy? Is it something the repair man could sort out?
He had a couple of Canonets, which I really liked the feel of. Really liked, in fact. One appeared to be working mechanically, whilst the other had a clear viewfinder and was complete. Combining the two might make one really good one, but that would mean buying both.
When I look at the stuff on ebay I wonder if I should wait until I am back in the UK and buy one that is working well, rather than buying a cheap, battered one and getting it repaired. That said, there is something to be said for rescuing these tired little things and bringing them back to their former glory.
Still loving the Olympus XA, of which there are quite a few on ebay, but slightly over my budget. Still open to suggestions and opinions!