No I don't work in a breakers! I'm a maintenance fitter by trade & part of that job is making bits fit together that don't usually. I bought a lathe off e-bay (£120) so that i could make axle spacers etc. The CBR rear wheel was quite straightforward, I had to machine about 7mm from the sprocket carrier - where the sprocket mates to the carrier face. Then I made a spacer for the brake caliper side, and a plate to weld to the swinging arm so that the caliper could be fitted and slide when the chain was adjusted. I went to a 530 chain so i could try different gearing but I had to modify a front sprocket cos the TR has a 630 chain. I used an XS650 front sprocket ( thanx mark! ) and had to drill holes in it for the retaining plate.
Because I was going to a rear disc, I made a new footrest plate to accept a master cylinder and moved the footrest up 1 inch & back 2, this should be better with the new bars. I've made this plate out of 6mm steel plate but with as much cutout as possible to save weight. It is heavier than stock but what can you do! I've almost finished the plate for the other side, again with a rearset peg - cafe racer style ha ha!
I just asked people selling forks on ebay, how long various ones were, then i got some slightly bent gsx750 ones for £10 - bargain! We have a press at work and they've straightened up lovely. Now i have to make the zzr600 yokes fit the steering stem on the TR1. The stem length looks similar, so it shouldn't be too hard I hope. You can buy bearings in various internal/external diameter combinations, so I hope to buy them without too much bother.
Hope that helps a bit, if you want some pics I can send you some when i've finished putting the rear hugger on - ducati monster - ebay again, i'm addicted lol.