Ah, I thought that might be the case. He's actually working on my Leica IIIf right now but I know he's only doing three days a week these days... last time we spoke he told me that he doesn't think he'll ever stop working completely as he loves it too much, but I guess he doesn't have as much capacity for the work as he used to. Shame.
I assume he'd be more than capable of dealing with a Leotax as it's mostly the same as dismantling a Leica, but with a couple of extra considerations. Basically, like most cameras, you just work you way around unscrewing and removing everything you see, but the lever wind and rewind knob both need a bit of special attention.
For one, the lever wind has a tiny ball bearing detent that
will get lost the second you remove the film reminder on the top; being aware of that before it gets lost in the carpet is handy. Unscrewing the central section of the wind lever to remove it is easy enough, but it has a tendency to unscrew itself through use after replacing it; I ended up putting a tiny dab of nail polish on the threads and leaving it to set before winding the camera, and that seems to have done the trick.
The rewind knob/crank is the worst part; there's two springs in there and rebuilding it is a fiddly pain in the ass. The only footage or imagery I could find of someone disassembling or reassembling a late Leotax actually ended with him looking at it very confused and leaving it to one side. I can't remember the reassembly process I went for but it was far more annoying than your typical rewind knob.
If it does go in for service with Ed, you might want to have him check the "pad" that isolates the flash circuit is still intact. You can see that here:
Leotax Flash Circuits
I could do, but I'm rarely in North London, and I'm going to be doing a lot of travelling in the coming weeks. I'd be happy to meet up for a drink and bring some screwdrivers if you can think of a place with a distant enough view to check the infinity calibration, though. That's normally all you need to do on these things - I don't think I've ever seen a Barnack with rangefinder issues at close-up.