A very productive day in the workshop today! I got the frame on the bench and trued up level and straight. I then got the headstock located trued and tacked on. Popped the forks in to check stance, ride height etc. All looks good, albeit I did have to raise the front of the frame slightly. However, I think I can lose a good half inch or so in adjustment and there'll be another inch or so, when the suspension compresses. Just leaving everything tacked for now, just in case.
I popped the engine in to get a feel for where it will sit and I'm pretty happy with how it fits. I had already removed the original bottom mounts from the old frame, so I used them along with some 10mm stainless bar, to tack to the frame. The frame is slightly wider than the original, so I'll thread either end of the bar and machine some spacers later
When I fitted the calipers, I noticed that due to the way they mount, there is not a lot of room left between them. In fact I think they mount back to front, as the rather nice aluminium piston caps are on the inside. I checked and they're mounted like that on the new bikes. Anyway, laced up a wheel to the old hub and popped it in. Indeed there is interference with the spokes. However, there is plenty of meat on the inside of the calipers, so I may be able to machine them down. Once I get some 22mm bearings, I'll mock it up properly and work it out.
Tomorrow I'll work more on the engine mounts. Due to the tank I'll be running, I'm not going to use a top mount on this bike.