Looks like a tap from an acetylene torch. Hovered at top then moved down. That would explain 1) loss of metal, 2) metal piling up on edges. It would melt, flow any harden quickly if just a 5-10 second tap.
Disclaimer: While a tremendous amount of effort goes into ensuring the accuracy of the information contained in this site, Coin Community assumes no liability for errors. Copyright 2005 - 2026 Coin Community Family- all rights reserved worldwide. Use of any images or content on this website without prior written permission of Coin Community or the original lender is strictly prohibited. Contact Us | Advertise Here | Privacy Policy / Terms of Use