FD, that is a rough job on changing out the starter clutch. Did you get the "upgraded' one with the extra support bushings? For the starter on mine, I took it apart, cleaned it up and put it back together, just been careful about starting process and making sure the tune was good on the bike to help things out. The body bolts on the starter, the long ones the run the length of it should be straight. If they are very twisted or something, then I would look hard for a replacement. If they are still in line, then you should have a bit of time to track down another starter.
Unfortunately I don't have any advice on the oil pump chain.