As in, he's a grown up feral kid?
I've always been fascinated with this topic too, and just have two visual tidbits to share:
-Recently referenced on Konnan's podcast, Animal tried to really play up his Road Warrior roots during a 2006 run. I vaguely recall him wrestling in black leather with no paint, but never saw him sport this cosplay jacket.
-You mentioned Demolition but it's worth noting they basically dressed exactly like Humongous from the neck down, even more apparent when they rocked their entrance mask, which was the coolest thing I had seen as a 7-year old.