I have just started to work on the brakes on my 46 2 ton as well.I have all the same problems you have and was also thinking about a different booster and master.There is a company close to you in Mooresville called master power brakes that have good tech support and a lot of good product.An aftermarket 9'' dual diaphram booster and m.c. for a mid 70's pickup may work O.K. They will get you fixed up there, but I don't know how hard it will be to get wheel cylinders sorted out. Keep us posted. Jim