Stinger size varied a lot across Kaywoodie shapes and time, so your best bet is still to find another 22. Also, I am guessing you have a press-fit stinger like that shown in the rebornpipes entry. I would not do what was done to that pipe. I would replace a press-fit stinger with another press-fit stinger in order to ensure a durable fix and proper thread match. I am completely unfamiliar with the press-fit stingers, but I would think several differences in procedure are required. First, I would heat and carefully pull the cut stinger with as little twisting or lateral movement as possible. The donor stinger can be removed as savagely as one likes, provided the stinger itself is not damaged in the process. Second, when inserting the replacement, I would probably want to use an epoxy to secure it. I would ask one of the resident pipe repairmen which epoxy they would use. Third, unless the press fit allows the visible portion of the stinger to rotate within the embedded part, I would make sure I had the stem alignment right prior to pressing in the replacement stinger.
The above is all hypothetical, as I have never messed with press-fit stingers. I hope someone will chime in with the voice of actual experience.