I have an old Holden 253 here, has been sitting for a long time, I have been hand turning it now and again..

I was thinking of putting it in an old ute I have, i have pulled the heads off to replace gaskets and have noticed there was a small residue of water sitting in one bore, this has created surface rust - When I say surface I mean when I use a rag and wipe it down it leaves a visible rust 'stain', if I try to polish it and rub hard with a soft cloth it nearly dissapears, when i run my finger over it I feel no 'pitting' on most of it, however I may be able to feel a tiny amount in a couple of spots near the top of the bore..

This is not intended to be a long term motor, could I use a 1200 plus grit emory paper to polish out the stains without having the rings explode or leak? Or am I wasting my time with this motor?

I have another engine being built, but it will be a slow rebuild due to funds, should i persist with the old 253 between now and then, or just wait it out?

Want to take the ute to Denni, so hoping I can get away with the old 253 for that..?