Dörfler & Jörka?Wasn't there a cousin or wayward brother of J. Keilwerth that made saxes with RTH out of Italy or eastern Europe at one time?
Possibly. I come on SOTW in the hope that I might learn something about saxophones ! I'm not sure at all whether the detail I've highlighted is a complete red herring and was commonplace with makers other than those in Eastern Europe. I'm certainly agree with Swampcabbage.........one hard knock and you could be faced with a challenging repair.Nice detective work!