Gerd,
I agree with Mikee's observation, it looks to be the "male" part of an embossing die. More than likely there's a "female," second part to it, somewhere? I've never seen such a massive mounting cylinder on any printing dies so it may have been for a special type of stamping/embossing/punching machine?
Whatever the case might be, it looks like you got the most important half of the die, as the female part would have been "wrong-reading."
A most interesting and unique item, very nice sir!
Best!
Bill
