Ouch! So sorry to hear that. At least you're OK and nobody got hurt?
Good luck on the parts search, I'm sure somebody here will be able to help you out.
Maybe it would be a good time to convert to a dual chamber master cylinder? Still scary when you have a brake leak, but at least you have half your brakes to get you slowed down.
'64 Parisienne CS "barn find" - last on the road in '86 ... Owner Protection Plan booklet, original paint, original near-mint aqua interior, original aqua GM floor mats, original 283, factory posi, and original rust.