All drums and no hope.

[burnin oil]

The others are on the track. One more thing you may try is breaking loose the lines and reseating them. I have seen some where they didnt 100% line up and leaked. Reseating the line squarely and retightening solved the issue.

If you do need to replace the proportioning valve I would suggest digging through Summit Racing. They are one of the few places that really stock them and have many combinations/options available. I have an old Dodge 2500 that I fought the brakes on and replaced it all. Brakes were still crap and you never knew if it would stop. I ended up getting the proportioning valve for a 70s chevy and swapped it in. That truck stopped in half the distance as it did new! It is amazing how much fluid can actually bypass inside those things.