I was getting not marring but a draw burr... the rivet head material would pull into the gap between the puller hole and the rivet nail. A piece of aluminum with a hole to fit the nail fixes the problem and when you use it it gets a little mashed so the hole gets tighter rather than looser.
Also I ground material from the puller for corner clearance.
John Bright, RV-6A, at Finish Kit
Continental Titan IOX-360, 8.5:1, vertical sump, SDSEFI EM-5, injectors in heads.
Aeroelectric Dual Alternator Single Battery/SDSEFI dwg ECUdual4, dual batteries TBD.