Still seems odd the abutment would be so inaccessible but maybe overlooked as simple until the body goes on?
But even then, a BONDED body makes the flaw so much worse!
I have a thought, get a longer cable assembly (S2?) and put a new forward abutment up where it is accessible.
Do you have or can you borrow a Bore-Scope?
Probably best if it has a flexible shaft.
There may be enough space between the chassis and seat to get a look without cutting?