I'm not sure Jim, maybe I'm rose tinting, but my instinct tells me that it was Koln traders alone.
I've read - somewhere in the past - that those markets employed smiths to stamp the blades according to the customer's needs.
Considering the variations in the styles of all those spurious punzones, that, to me, seems highly likely.
I just feel that the Solingen guild workers were above that sort of knavery. Just a feeling. Dealers
! You know, they are a different breed!
Also, as far as I am aware, no-one could deal directly with Solingen other than authorised agents.