You can do a sleeve in the case for the shift shaft.
OP, find an image with every nut and bolt of the entire motor. Either in a microfiche, clymer, etc. But make sure you not only see that you have everything, but check the condition of every component. Rods for the shift forks, eccentric hardware, new clutch retaining clip, bronze bushing on the clutch ok?, case studs, clutch arm hardware, EVERYTHING. Jeff has a pretty decent website, it helps to just go page by page in the OEM section and just get almost everything new.