So One u-joint bolt fell out and 3 were attached but no spin to axel? Or is U-joint destroyed too?
One bolt fell out, but there was only some minor nicks on the yoke, so everything looks okay around the U-joint so far.
I think someone has previously installed an oakie bushing. The original front bushing is only about 1-1/2" long, so if that was all that was in there, you'd be able to see the splined driveshaft behind it through that gash. The rear dowel pin has been removed to allow the rear bushing to be pushed back by the oakie bushing.
Since there's that big hole in there, you could weld a piece of metal to the bushing to allow you to hammer it out.
Also since there's a dowel pin hole, you likely need to use the earlier (smaller diameter) oakie bushing. That might be the cause of the gash near the front end - someone going crazy getting the original bushing out.
So there is a ~1 1/2" bushing in there that I am trying to remove. In the photo, you can see about a 1/4" gap between it and whatever that is (maybe an okie - but then why the standard bushing?)
Considering the amount of deformity and damage that torque tube has suffered, maybe it's time to locate another one??? There are very frequently complete torque tube axles that come up for sale as many folks swap out for later model rear axles or convert to open drive differentials.
If you decide to go the replacement torque tube route, post an ad in the
Truck Parts Wanted forum and we can try and help you locate a replacement.

Honestly, if it were another 10 or so years down the road when I am hopefully able to be retired, I would be all in on doing something like you suggest. Right now though, i just need it to survive until then. If I can just take it out every once in while for short distances, that would be enough for now. Outside of work, I have many other projects occupying my time and I don't have a nice place where the truck can sit for weeks on end while I work on it (I am working on it in my side gravel driveway right now).
Like I said in my introduction, this was my uncle's and when he passed last year I brought it to my home. I am super grateful to have the truck and it means even more because it was my uncle's. But the timing isn't right for me to be able to put a lot of time and space into working on it.
I appreciate everyone's suggestions and help. I'll let you know how this progresses.