72 Duster Resurrection
Just checked rock auto. I dont know if you have 9" or 10" drums, but the wheel cylinders apparently are the same left and right in the back, but left right specific in the front. They are pretty dirt cheap about $3 to $5, the right front is about $14 though. The brake lines are pretty cheap at $7-$9 each. Master cylinder isnt cheap. Hopefully yours works.
If you dont have them, theres 3 brake tools you need for doing drum brakes. I got mine at sears long ago in the mid 1980s. You need a star wheel adjusting spoon, a spring cup remover/installer, and return spring remover/installer.
If you decide to do the brakes, shoes etc, pay close attention to location of all the hardware and which shoes out of the set have more lining on them. Its been a long while but i believe the leading shoes at each wheel have to have more lining on them than the trailing shoes at each wheel.
Also only pull apart one side at a time, so you can use the other side as a point of reference seeing where everything goes and how it fits together to put it all back together
Specialty drum brake tools below. A very cheap way to save you cuss words and skinned knuckles. The brake spring cup removal tool 3rd pic below, mine is made by lisle, and has a different sized cup on either end making it more versatile. I couldent find a pic of it online though.