planertired,
Techincally, as a professional in the field I would never council you to disable/remove any safety device on an automobile. So, let me say this:
If we were converting this machine for off-road or racing use, we'd remove the device and use plain plumbing fittings. We would also have the customer sign a statement to that effect.
Beyond that, it seems as though you have a master cylinder problem. You will need to overhaul or replace that component at the least, I think. It's actually a better thing by far to lose your rear brakes than your fronts, as they do most of the work in stopping you, and impart stability. If only the rear brakes had been working we might not be communicating about this. When only rear brakes function, you lose all controlability in an emergency, or even a moderately hard, stop.
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon