Straightening "bent" coins
Some years ago I had a $10 early Bust eagle that was a PCGS MS61 that the dealer said should upgrade at NGC come back as "bent". I asked him if there was a way to fix it. He said he could try, sandwiching it between plexiglass in a vice, but no guarantees, he would charge $100 for the service. I said not worth the chance. He sent it back to PCGS with the grade insert and it came back as a straight MS61.
I have a Bust dime that came back as bent, it is hardly noticeable. Is attempting to straighten silver, gold or copper nickel coins always going to be very hard to do without damaging them permanently as metal has a memory?