Am I justified in my frustration?

Love how you guys jump on the “That’s dangerous” argument and try to insult me not building rearends when you see this piece of **** rear wont come apart even by pulling it with a 4x4.

All I need to do is get a rearend apart. I send 3rd member to SD Gear and Axle. So what if I don’t build third members. Moot point. I’m not allowed to send a 3rd member to a shop? That's what you're latching onto now to tell me I'm not justified in being frustrated?

You still have to be able to disassemble one to be able to call it rebuildable. The seller says he has no reason to believe the diff is not rebuildable but what's the reason to believe it IS rebuildable. This was a mystery rearend to him but since it's not "rusted like a backeast rearend" ...... Well, my bad for trusting a guy based on his affiliation with a reputable club and a FABO member.

if I had to cut a window in the housing and cut the axle apart at the gear set to pop the third member out.
Would it still be considered rebuildable?

Honestly, As others have suggested I think the slide hammer is going to be the only way to get it apart....curious if what you tried was similar.

I just tried a regular slide hammer that I've used to pull several other 8-3/4 axles, WD40, PB Blaster, MAP gas and a butane torch. All that before I even reached out to Troy. After I told him I tried all that he said he wouldn't help me out multiple times so I started this thread. After it's creation he came to me with the '$100 and shut up!' deal.