Drew, do you know if any certificates exist that accompanied the tubes or tubesets? Considering the misspelling and W(so that they would know it was Whitworth?) on the flats, WC seems to have another point that the makers applied the stamps. Apparently the American makers did not follow suite. I would tend to think that these tubes used by the American makers were sourced along the same lines as all the rest, Cockerill, Krupp, etc.

Kind Regards,

Raimey
rse