What do you think of the Yashica, Nick? I've seen them on the 'bay for around £100 or less. How's the RF patch - clear and bright or would I have to get it serviced somewhere?
I've also got an Electro 35GT and can give you my opinions and recommendations.
The Electro 35s are fine cameras, well constructed, with an excellent lens and are superb for hand held and tripod mounted low light photography. The prices seem to be very volatile and are high at the moment. This is probably because they appear to have developed a minor cult status and have become a retro-chic fashion accessory with urban hipsters. Having said that, I would still buy one but I think £100 is too much, as you can get better value with other makes. I think I'd run to £70 for a good one.
I also have a spare parts 35GT, an MG-1 (it's less capable sibling) and an OM1. The rangefinder patches have always been well defined on my models and focusing is therefore quick. For a rangefinder, it's a big heavy camera, equal in size to many SLRs and less transportable than the OM1, as you can't put the lens and body in separate coat pockets.
It has two common defects that I know of. Firstly they often seem to have suffered from corrosion due to battery leakage. This is probably due to the fact that the original mercury battery was rather large and presumably capable of leaking copious amounts of gunk. The corrosion often attacks the top terminal and eats away the main power wire. This is a relatively easy repair, requiring only the removal of the top cover and a small re-soldering job.
The other problem is what someone over dramatically named the 'pad of death' and the name stuck; I'd just call it the' rotten rubber pad'. This stops the interaction between the metering and the shutter timings working correctly. You can Google for the details and Yashica Guy describes how to fix it. This repair requires a major disassembly - tedious but not intrinsically difficult if you take it slowly. Some folks say you can fix it by just removing the top but I say that you can't do a proper job that way. The majority opinion, which I share, is that if the camera clunks when you advance the film, then the POD is OK. Certainly my 35GT and MG1 both clunk and exposure is fine.
Finally, you see many listed on e-bay as 'excellent working order but I haven't tested it with a battery' which I would interpret as 'I have tested it with a battery and the shutter clicks but the electrics are shot'. You need to know that the both the under and over lights operate when the camera's pointed at an appropriately lit subject.
Here are links to a few low-light shots taken with my 35GT, the first two are hand held.
https://www.flickr.com/photos/47119506@N03/10208392504/
https://www.flickr.com/photos/47119506@N03/5731659341/
https://www.flickr.com/photos/47119506@N03/4532401928/
Good luck with whatever you go for.