wheel cylinder rebuild question

I didn't know anybody rebuilt cylinders anymore, seemed to me that new ones are not much more than the kits.

The big thing is to hone it and inspect the bore for pitting. This is a judgement call.

Be careful with "adaptors." You might have something odd like a mis-boxed cylinder, and you might have a front one that's designed for a direct screw in hose with a copper gasket, rather than a metal tube with inverted flare seat. You might get "something" screwed together, alright, but not properly seal.