More "expert" opinions will follow. And with the caveat that I really can't tell how deep the corrosion is, I'd first of all take steel wool or some 320-400 grit sand paper (after stuffing a clean shop rag in the cylinder below the rust) and with a little spray lube work on the rust to see just how deep it is. If as superficial as it appears, next step would be to reassembly the engine, install and enjoy. If it's not just surface rust then I'd hone it till it was near perfect. Then move on with a good cleaning and reassemble, etc, etc.
Good Luck,
RonR
Last edited by moparguy; 12/08/2019 4:20 PM.