[DirtyLarry]

I don’t know if I agree with your mechanics assessment where the hydrobooster is your problem but any parts store can supply a reman hydrobooster. When a booster, vacuum or hydraulic, fails you lose brake pedal assistance and the pedal feels hard to step on. The problem is most people don’t understand hydroboost and tend to over complicate it in their thought process and blame it for issues that are really master cylinder related.

Napa lists both hydroboosters as well, which I believe are rebuild by A1 Cardone as TX Firefighter listed.

527252 w/O-ring type - MSRP $287.16
527918 w/ Seat Type Port – MSRP $305.60

Heck, even the dime store part stores like Autozone list both of these part numbers on their website. Those too are probably A1 Cardone rebuilds