numbers on the top of the head read 9685H also the piston skirts have half moon cut outs on them is that a normal thing?

then it also has 534 on the bottom

so what are my options for a replacement cylinder?

BTW only one side has a gouge the other is clean, just to clarify. Yea its all been in there a while. I'm beginning to think that the PO did a "rebuild" using the same internal components to put it all back together thus causing this.