Re:
It's original. I've had it for around 10 or 12 years at least.
The original ones didn't have logos I don't think, later ones did.
The l-bends, the silver one is original, the black is a repro. Don't have the bolts, not aware anything special is needed. I had one fitted with the serrated washers, but never seen the need for them, especially as I've only used these cages for decoration.