I purchased this Bogner head recently with a bunch of guitars, and I just dug into it this week - what a monster!
The amp was owned and used by Mark Goldenberg, a Bogner endorsee and a monster player who plays, writes and produces for a laundry list of awesomeness. I have some email confirmation and the Anvil case bears his name. https://en.m.wikipedia.org/wiki/Mark_Goldenberg
The amp was said to be a prototype, but I think that all Caveman amps are kind of prototypes - the model seems to have never been launched. A Google search for Bogner Cavemen will dig up several postings - check it out.
The amp is in excellent cosmetic and functional condition, but the footswitch seems to have an issue- it won’t change channels, but the switch on the back will.
Anvil case included.
In the pics, the standby indicator light bulb is missing. I have it, and it’ll be included but not waranteed