Many years ago when I was putting the final two coins in my Eisenhower dollar album (1973-P and 1973-D from a mint set), I noticed that my 1976-D Variety 1 dollar was missing the mint mark! 
How did I go so long without noticing that? I think it was because when I got to those dates on my look-throughs, I spent more time looking at the reverse than the obverse.
I immediately went back to that coin dealer to get the correct coin for the hole. The duplicate is now in one of the four undated holes in the Eisenhower dollar Dansco. I get a good chuckle every time I see it.
How did I go so long without noticing that? I think it was because when I got to those dates on my look-throughs, I spent more time looking at the reverse than the obverse.
I immediately went back to that coin dealer to get the correct coin for the hole. The duplicate is now in one of the four undated holes in the Eisenhower dollar Dansco. I get a good chuckle every time I see it.




















