1964 dart brake problems..

I pulled the wheel off, piston is not moving at all, looks like someone tried to unfreeze it by tapping with a hammer, both sides have hammer markings. So now I have to make a decision how much to spend and how far to go with this... anywhere I look it’s a new project lol
I haven't bought wheel cylinders in a long time, so I don't know what the price point is, if you can somehow break it free a rebuild kit is pretty cheap, but you'll have to buy a wheel cylinder hone, so you have to factor that in.
Have you checked RockAuto for the wheel cylinders? the pistons are probably aluminum, so if they are seized there probably was water in the system.