Jim, had these come off on a 7603 years ago,
mine weren't broken just bowed. On the 7603 I used a pencil eraser, the large draftsman type
and pushed/wedged it between the shell and the adjacent PC board. This held the shell against the contacts
and its still working many years later. I would send you a pix, but I plugged my 7L14 into my 7603 a year ago
as a permanent fixture and just found it jammed in and cant unplug it without fear of breaking the pull tab
Many plug ins inserted and removed b4 that with no probs.
The 7603 had an LHS plug in shell come off too, and since there is no pc board adjacent that I fixed a small
Al bracket on the frame to hold that one in with the compressed eraser.
I used hi quality erasers , Staedler, which have stood the test of time , maybe hard to get now with the demise of
penciled/ inked drafting? Maybe you could use two to press in both glued halves?
Cheap and quick enough to give it a go