Making the best of a bad situation

i'd throw the power booster in the trash for starters...

leave the prop valve in there, source a drum/drum dual master from rock and then either hunt down a stock pushrod or grab an adjustable from dr. diff

the adjustable that you have in there looks sus AF and who knows what cobbled together BS that is. so adios to that.

for my own edification, i'd run back on the previous work and make darn sure everything was dress-right-dress with the parts: correct wheel cylinder, correct bearings/hubs (and adjusted properly!), correctly plumbed and routed, all hardware present and accounted for, installed properly, etc.

personally though? i'd just bite the bullet and go disc. yeah it's another chunk of change, and a whole *** bunch of work; but the net positive of great performing, easy to service and available parts would make the investment well worth it.