welcome to the site!! that is a sharp looking truck!
I believe the 59 is the same as my 58. Yes, 2 wheel cylinders per side on the rear. There were 2 different types, one with solid rubber cups, the other one, the cups are actually rings that fit over the piston. I don't have cylinder part numbers, I just put kits in mine. You should be able to get the kits and/or cylinders at Napa. Rock Auto may also have them.
