Cookbw
Neither of those issues are of major consequence.
Both are easy to cure and cheap.
Unless you don't do any of your own wrenching. When owning a 40 year old car that can get expensive.
1. the center bearing can get old/torn and allow the drive shaft to move more than it should during acceleration. Or junctions need to be tightened and realigned. Other parts like trans mnt also.
2. 5 sp only has 7 places for it to leak other than the cases. Input shaft seal, output shaft seal, shifter seal, light switch, speedo o-ring, fill and drain spots. Only one needs the trans out for repair.
HTH
If you need further info just ask!
steve