I too picked up a 5/35 husk, decommissioned out of the GA school system, for (oddly enough) $535. Mine has the same heel break, only with a not-so-great, didn't quite get the ends flush, repair. I suggest a more nuanced approach to diagnosis as an alternative to removing a bunch of things just to see what "might" be wrong.
String the bass up, only bring it up to standard pitch very gradually, like start it a fifth below at BEAD tuning and raise the pitch incrementally 1/2 step per day. Any weaknesses or potential failure points ought to reveal themselves by slow separation, and you may be able to wick some glue in there and clamp and thereby avoid some major surgeries. And also avoid the explosion that might occur if you run the strings up to standard pitch right away.
String the bass up, only bring it up to standard pitch very gradually, like start it a fifth below at BEAD tuning and raise the pitch incrementally 1/2 step per day. Any weaknesses or potential failure points ought to reveal themselves by slow separation, and you may be able to wick some glue in there and clamp and thereby avoid some major surgeries. And also avoid the explosion that might occur if you run the strings up to standard pitch right away.