The tubeset initials of >>JT<< could easily be Jules Thonon who in February 1912 filed for trademark protection for >>Canons D'Armes a Feu<<, which is not on these tubes. Too, I assume the tube steel is John Cockerill - Seraing of Liège.

Of Course Joseph Thonon could be a suspect but I am not sure if he rolled his own?

Hochachtungsvoll,

Raimey
rse