As long as the master is a disk/drum unit it shouldn't matter in your application, unless your concern is originality,....seeing that your car was "converted" to manual disk, perhaps the swap isn't correct, linkage wise?,...sounds like residual pressure from the master is present,....are you able to pull the brake pedal up from it's current resting position?, if it's already against the frame stop, try disconnecting the pedal linkage, and jack the offending tire(s) off the ground and attempt turning,....BTW is the pedal push rod an adjustable threaded manual unit?

You got to do a little "diggin" and supply some more info

Mike