Klaus,
out of interest - what era would you say that u87 is from? Would I be wrong if I thought it was an early seventies one?
I say this because the model number is indicated only as u87 as opposed to "u87i" and the components on pcb look similar to my early seventies u87 (which to my ears sounded better than any of the four or five u87s of varying vintages and revisions that I have owned)
Also is it just me or does the lining in the top of the case he has it in look collapsed? Generally when I have seen the foam in those cases collapse it has left a horrible damp, tar like gunk of decomposing foam that would be the death of any capsule that came near it.