I have Selectro hubs on my cruiser, as near as my dad, previous owner and I could figure, the first owner put them on. I still have the driveplates, but like to have hubs to save the wear and tear on the front end.
Personally, mine appear to be fairly well built, almost as good as Toyota hubs. I'm surprised that the base part exploded on you TJ. Mine say heavy duty and look very similar to yours, but my outside cap is bright chrome, and not a speck of discoloration on it, and the other part of the case is solid steel, very similar to an Aisin. So apparently at a later date they went to a cast aluminum or something, as mine are machined steel.
I'm repacking bearings and such right now, and took the hub off the passenger side and disassembled it right fast last night so I could the O ring out to take into the parts store for a replacement. The ramped, cam piece that screws to the ab is broken. I have already replaced the other side, as it was broken before. Too bad, the original piece is metal, pop metal of some sort, but metal, the replacement piece was plastic. Probably wont crack and break, but the plastic feels soft when you turn the hub to engage and disengage, probably will wear faster too.
Can you put newer Toyota hubs on a 73 FJ-40, do you just change the outer birf peice to fine spline and get the proper length hub, or does it entail a knuckle swap. Personally don't mind drum brakes, don't want to swap out evertyhing.