Just got to thinking about something interesting. 1922 was a big year for Lincoln cents because of the 'no D' variety (Philadelphia didn't mint any coins, but a small percentage of Denver coins were struck from polished and worn dies that erased the mintmark). It seems unlikely that this was a unique occurrence (i.e. that ONLY in 1922 was this sort of die erosion and maintenance happening). The only reason these cents stick out like a sore thumb is because there were no 1922 cents minted in Philadelphia. So, odds are, there's 1923 'plain', 1921 'plain', and probably all kinds of other 'plain' coins rattling about out there, minted in Denver or San Francisco (or maybe even in New Orleans earlier on), that will forever be stuck in 2x2's as their Philadelphia counterparts. Heck, maybe there's a 1914 'plain' out there that is one of those 2-million or so minted in Denver. Or a 1909 VDB 'plain' that was minted in San Francisco. Now, because of the value of the 1922 'no D' cent, experts have spent a great deal of time cataloging the unique die characteristics of the four die pairs that produced these coins. Wouldn't it be interesting if, using die pair characteristics, other coins that 'appear' to be minted in Philadelphia could be proven to have come from the branch mints? Of course, these coins won't have anywhere near the value of the 1922 'plain' cents due to the lack of publicity or popularity; I just think it's an interesting thought.
Not impossible, but there is one key factor that existed in 1922 that, at least not normally, did not exist in the other years. There was a shortage of dies and they were trying to extend the die's life beyond its normal life. To some extent, that is why so many 1922-D (and no"D") were so poorly struck.
