I'm afraid I haven't looked at APUG for a while and wasn't aware of this thread
I think I can help you understand your focus problems, Tim, if not solve them.
The V35 'auto focus' system depends on a cam to adjust the lens as the head is raised.. I can't remember if each cam was machined to the individual lens (being Leica, it wouldn't surprise me, if they were) but I'm absolutely certain that you needed a different cam for a Leica Focotar or a Schneider lens. You bought the enlarger ready cammed with your preferred lens.
The reason why there are lots of V35's with the "wrong lens" is because those Focotar lenses were highly desirable and very easy to unscrew in a gloomy darkroom. When a photographer or lab went out of business, it was probably the easiest things to 'liberate', especially if you were a disgruntled employee being shown the door. You'd often see V35's for sale without lens for about £100 - they were quite common - and you'd substitute the missing lens with anything you could find, accepting that it wouldn't correspond to the cam.
Having said that, even with the wrong lens and having to focus manually, it's still a fantastic enlarger. Also, bear in mind that you can only set the autofocus for one baseboard - if you change baseboard regularly, the a/f is a complete waste of time.
As for carriers, I managed to get a spare from Alex at Mr Cad a couple of years ago. I also seem to recall him telling me that the Kaiser carriers would also fit.
Much as I like the V35, I used to prefer the older Focomat. Also an auto-focus system but with a condenser head, not a diffuser. Sharper and harder than the V35.
Oh yeah, almost forgot, I've got a used V35, with original lens, in the garage if anyone wants to make an offer...