I have a 1945-D Mercury dime with a very noticeable doubled mint mark. I believe it is likely a fake, it is slightly overweight (2.6 grams), doesn't pass the drop/ping test, reverse looks warped, etc. Just thought I'd share and see what others think.
Sorry Iím a few days late to this topic but I do have something to add.
I donít see why this would be faked, itís a common date. The RPM is legit, itís RPM-001 as said above. The warping on the reverse is just normal die wear and progressive indirect design transfer, fairly common on late die state 1900s US coins. http://www.error-ref.com/progressiv...gn-transfer/