In one picture I can sort of see a metal tab bent up, suggesting the locking mech is fused in place/wont slide back and forth. I had this on a game once, took the whole cab face off

In this case... break glass, take off the top bar and lift pf out from the top, disconnect it etc. With the pf out take off the shooter and then the 6 mounting screws for the receiver and you should be able to remove the bar and receiver as one piece. With a little luck you can salvage the bar and then one of us can provide a new receiver assy. They are also on ebay...