I built a Cranbrook. I used the rag joint rear sprocket assembly until I got the Nice Aluminum piece from Manic Mechanic. That is a class piece and it allows perfect lateral adjustment of the sprocket.
The rag joint.. I had to thin the pieces on the outside of the spokes next to the sprocket to get it to line up properly. I thinned them by using a band saw. Be careful if you do that since you have to hold the pieces some how.
It lined up fine but it is not a precise thing when tightening down the nine bolts you could get some wobble in the rear sprocket.
I took enough links out of the drive chain that the hump going over the chain Idler was not a radical change in direction.
I added a Front brake and a mechanical speedomoter.
The fitting from the gas tank on mine was in an awkard position so I had to extend it and add a 45 degree angle to get it to clear.
The split end clamp joint on the intake manifold to the Carb is hard to get a good seal.
I am going to tackle that issue soon. Thinking about trying to put a thin plastic hose piece over it with a couple clamps if I can get that to work.
Hope none of this scares you off. If you have some mechanical ability you can solve all these issues.
Pictures here: Motorbike
For the last few years I built and repaired Mini Sprint race cars that are powered by sportbike motors so I had to make a lot of parts, brackets etc.