I assume you mean the housing. If you can JB weld it, and you might be able use it without that stud.
When I took mine apart, I cleaned the reflector side of the housing. Taped off the sockets, sprayed the the housing with high temperature chrome paint.
DO NOT over tighten the housing. If you need the whole taillight gasket set, Detroit Muscle Technologies supply a set.
I have housings, but shipping now days might be tricky. You could try
chargersbyjim@sbcglobal.net or Gary.
Classicchargers@outlook.com. Both are in Oklahoma. My email
iweeks@sasktel.net. Good luck Ian