If you're going to have someone else check it out, then take the shaft to the local shaft builder and have them change out the antique ujoints you have there and then spin balance it. And be done.
It will be the best $50-100 you've spent. They will be able to tell you if your shaft is bent. If you still have the stock control arms and motor mounts, then pinion angle checking is kind of a pud puller as well.
I looked up your location and there is a Fleetpride within 40 miles of you, and I'll guess that there is someone local that can fix you up. Find a local speed shop and ask them where to take it. Every racer has a custom made driveshaft.