Kurt at Cruiser Outfitters has a good tech page on drive flanges that might help you id your mystery shafts here:Not sure if the nuts used on the brake drum were too large as far as wrench used or wrong SAE wrench was used. Ended up pulling it off the shelve to remove the nuts. Was when I did I noticed dents in the main tube. View attachment 1832646 View attachment 1832647
Interesting the driveshaft I believe were from my 73 have the same pattern but used smaller bolts. Which brings up the question does my 73 have smaller holes in the flange or are 73 driveshafts somewhere else. Anyway have a driveshaft while not as bad as yours it does have some dents.
Cruiser Outfitters
I appreciate you looking through your parts for me but I'll pass on the rusty shaft. My best option might be to re-tube or sleeve my shaft and take it down to Tucson to get it balanced.