Geno:
The sound is like one big thud. I don't know to whom it might belong, but it is a forge mark that pairs with the "Krupp Stahl", Krupp Steel, stamp. Thanks for the pic and I'll add it to the list. I think the dual stamp is for a multiple effort on the example and it tracks compensation as well as liability. Maybe a tube maker who cottoned to oak leaves? A general consensus is that there were a couple of talley books, one for each craftsmen who added effort to an example and one for the gunmaker/contractor who got the order and subed the work out. So one of my questions for now is what was the frequency of the payment for services: 1 week, bi-weekly, once a month?

Early on there was some schools of thought that the stamps might question the integrity of the steel, but I think proof test proved otherwise. Besides the proofmarks, the other marks note the effort of individual craftsmen in the overall effort for the example. Sort of like a completed work-order on the gun. Now if we had the work order, we just might make some headway. And it may be that the paper work order was an aid to the overall contractor in keeping the talley.

Kind Regards,

Raimey
rse