Does the date on this coin look altered, or am I just seeing things? https://www.ebay.com/itm/1921-D-Mer...hMAAOSw9tNdgXCz:sc:USPSFirstClass!44067!US!-1
I agree with @Collecting Nut. If you look closely most of the lettering is worn into the rim and distorted. And you would have to think why somebody would alter a 21-D in that shape. There wouldn't be much to gain for all that effort. I think it is correct but damaged as well.
Actually, to me, it looks like a small die chip "attached" itself to the 1, & now it's worn along with the rest of the coin. JMO