Underweight LMC, Need Expert Opinions

A friend brought me a group of coins to examine that belonged to his grandfather. Along with trimes, Half Dimes, Barber coins, morgans, etc., was this Memorial cent.






As you can see, most of the rim is gone. I stacked it on another Memorial cent to compare what was missing:




The coin weighs 1.5g, and has a very thin profile compared to another Memorial:




My first thought was that the rim had just been sanded/filed away, but looking through my loupe there weren't any obvious tool marks.




Then I started looking at the weaknesses in the strike, and thought I should post it on here to get some opinions from you guys.