On my first fret-leveling project, I sanded/filed down the high frets, without realizing that maybe I should try to re-seat them first. That worked, but I did take a good amount of metal off of a few of them. Yesterday I worked on a beat-up GIO. I braced the neck well, and lightly hammered the high frets with a dead-blow hammer. I used a piece of acrylic to dampen the blow, and to land the force between the strings (still at tension). Of course after I got the two high ones down, others were high, and I ended up tapping down all the frets, then cleaning up the one or two troublesome ones. I was able to go up and down the neck until there were almost no high spots at all, without any filing. I would have never attempted either project, but both basses were picked up cheap on CL, already well abused. They were essentially useless for playing. But now I'm wondering- will the frets I pounded down pop out again, or was it possibly due to long-term creep, or a few bad events in their past? Will the ones I sanded pop further? At what point do you decide you have to refret vs. repair on and old bass?