I found this old add dated 1922, I believe I had seen on the wonderful web site shotguncollector.com also probably lifted from there so must give credit to our European Friend( absolutely wonderful work Sir).
Translates We machined to ensure that the stamps on the finished Lauren must have this exact wording; every deviation versatile the counterfeit
Seems to say that the German made Krupp steels were only called this if authentic German Krupp as of 1922.
I assume that means all other names except these were not licensed or from other licensed companies in Belgium?
Do we actually have the tensile strength of these specific 3 steels? Seems like the 3 ring special gewehr lauf steel numbers are all over the place?
I know this has been written about many many times but I thought someone could nail down these three with this wonderful 1922 add?