Herbert,
Maybe it could be him, but I doubt it.
Kulnig is an old Ferlach gunsmithing name so no problem there.
But I've never seen Ferlach initials on rib, only full names. But there are initials hidden inside of course.
Also I'm still inclined to think TK is a Czech gunsmith who sleeved the barrels...

With kind regards,
Jani