Driveshaft Mistery???

I wouldn't worry. Just determine the yoke, or keep the yoke, or sell the yoke separate

Determine the joints, measure it C-C length and OD and sell it based on that and what you just posted above, IE "what you think you know."

Here's the thing..........why does it matter? If someone can use it, they will. If they need to shorten it , they will.