Pre-68 Dave hit it on the head. If you have trouble finding somebody who can contour your shoes (and this is common today), you can just replace the drums and shoes at the same time. New drums and new shoes will be made at the right contour or if the shoes are off it will be very slightly and this will adjust itself as you drive pretty quickly. If your drum brakes are in good nick, they'll stop you just fine. One other suggestion: the last master cylinder I bought came from Rock Auto and was sold under the Cardone name. It was made in the USA...even the rubber boot was marked made in the USA. If you need a new one, you might consider this as an option. The last wheel cylinders I bought were also from Rock Auto and were made in the USA, but I can't remember the name those carried. I did some study on this after receiving the master cylinder and learned there is one private company in the USA still making master cylinders, wheel cylinders and other cast parts...or there was at that time. I suspect Cardone is buying from them and packaging in their boxes. This was the one:
https://www.rockauto.com/en/moreinfo.php?pk=3251646&cc=1487426&jsn=415
