Lovely ride. Hmmmmm. Clutch gradually tightening sounds like its gradually expanding, for reasons unknown. I mean, the tolerances are pretty small. Maybe there's some non-standard plates in there, or possibly there's a specific order the clutch plate pack. Like, there's a first one, and then all the rest can go in any order. Just a thought. Rough running, Fuel+Air+SPARK, so don't exclude that from the investigations. Sounds like a right bastard to hunt down though, and getting random ideas from me isn't going to help really. Could you potentially be having a flooded float bowl in one of the carbs? The needles on thumpers can get sticky after a while, and while your bike is a lot smoother, it may just be getting used to running again, and shaking out a few issues for you to educate us with. Anyway, best of luck.