You deserve a Bravo at least for carrying out a fiddly and awkward repair.
I looked at the GAK tuners, they look fairly low cost, the plates are just folded, it doesn't give great support for the worm shaft but better than nothing. Schertler tuners are available from Stewmac (USA) and are very
nicely engineered, they just look a bit like office furniture. I suspect that even cheap tuners are available in left and right versions. £25 is cheap for a set of tuners.
Roller spacing doesn't seem to have been standard in the early days of mechanical tuners. 35mm is the modern standard with at least one manufacturer making a 39mm set. I think it was Landsdorfer (taken over by Reischl) who made a 36 or 37mm set, just can't remember now. I had not heard of a 32 mm set, it doesn't leave much room to turn the buttons. If you wanted a special set made then perhaps Rubner would give you a price? They mass produce tuners in Germany and seem to make good quality tuners at a reasonable price and I am told that they will make special sets. There are specialist makers who will make whatever you need but the price is high (several hundred pounds) and there is usually a waiting list. ( Rodgers, Graf, Scheller, Allessi etc.)
"When I was younger, I could remember almost everything, whether it happened or not." Mark Twain