I had a Superleggeri pedal that was as you described. The damage was on the lead in or first turn of the thread . I used a Tri-file to get the damaged area smooth then carefully chamfered the end of the pedal on a grinder. It started in the crank ok but was still a bit snug. Thankfully I have a really long Eldi pedal wrench that got it all the way in . I did use just a dab of grease to aid in the turning of the pedal and to keep it from tearing the threads in the crank.