I'd get 2 brass male inverted flare plugs from the "Edelman" cabinet at your parts house of the dia of the M/C ports (maybe 2 diff dia's) and take the lines back off & plug them. They're cheap & you WILL use them for diagnostics in the future. If the M/C is good (& bled out) the pedal will now be rock hard w virtually no travel. If good there take out the rearmost brass plug & hookup & bleed out the fronts & get them till the pedal is again high and tight then hookup the rear drums & same deal. The only caveat I can think of happening in the procedure is if a bleeder screw(s) ain't being closed all the way before your helper lets up on the pedal.