If the hole is slightly enlarged but not big enough for the next size, you might try pre-squeezing a rivet.
Just take the next size longer rivet, if necessary, and just squeeze it in your squeezer a little. This will fatten up the rivet and likely fill the hole much better. Basically, a home made oops rivet.
RV6, RV8 (2), RV12 & RV3 about 2/3 done.
A&P, Tech Counselor & Flight Advisor