I removed those bolts by drilling a 7/16 hole inthe frame directly below. Slide a socket on the inside, pushed an3/8 extension though the hole into the socket.
I use a stock 78 master. I replaced the rear residual valve with a front residual valve, (both have same restriction) from a bad master. I use the stock fj40 proportion valve (no adjustment) both winter and summer, loaded and unloaded, and have no trouble with the rear disks locking up before...
I use the industrial rubber floor mats found at home depot. They are 5x7 carpet type material on top. Less than $20. Made mats for the front with cut extra
AS far as the clutch slave, I suggest buying a new one and rebuilding the old as a spare. (just in case). When you put the new one one check the old for scores in the barrel.. That is what make them fail 99% of the time. Hone it out and put in a kit.
Haven't done it on a cruiser, but have repaired others by soldering. Trick is to keep the solder out of the middle. Usually I pull out the knob and wire, solder the sheath and tube together. Then take a long bit the same diameter as the wire and clean-out where I soldered. Reinstall the wire...