If money is an object- in the 70s when I had no money to spare I had a gudgeon pin work loose and seriously scored the bores. Acting on the advice of a very well respected Seven engine fettler, I replaced the errant con rod but left the bore alone. That engine went on to run in countless trials and the odd circuit race. I never noticed an oiling problem and only swapped it because I’d built a big valve block I wanted to use. What I’m saying is don’t worry too much. Find out what is is, fix the rings or the con rod. But, it should be fine.
Alan Fairless