As I thought about this topic, I realized that there is a nerdy, but related, topic that should be considered with it: the mint's
intentionally-created minor doubled dies.
At least two dates in the
Lincoln Cent series have intentionally-created doubled dies: 1941 and 1949.
In 1941, two different hubs had the second "T" of TRUST break. One of them also had the first "T" of TRUST break. Multiple dies with broken "T" first hubbings were then re-hubbed with an intact "T" for the second hubbing. That there are so many of these intact-over-broken-T dies strongly suggests that the second hubbing was done intentionally to make the "T" look better. On many (and possibly all) of these intact-over-broken-T dies, the four in the date is also doubled. My examination of the shape of the rehubbed four
suggests that it is not a match for the four used in 1941. It more closely resembles the four used in 1940. (All eleven of the fours in the decade, including both fours in 1944, are different.) My best guess is that the Philadelphia Mint used a 1940 hub with the last digit ground down. On two die pair, there is a
very weak impression that strongly
resembles the zero of 1940. (Note my hesitation in asserting that it
is the zero.) It is centered exactly where the zero would have been in 1940, relative to the rehubbed four. That isn't enough evidence to state that this is what the mint did, but it suggests that more study needs to be devoted to this date. There are far more rehubbed "T: Philadelphia coins in 1941 than Denver or San Francisco coins. The easiest explanation is that the Philadelphia Mint made what they believed would be enough dies for Denver and San Francisco early in the die preparation cycle and shipped those dies to the respective branch mints. Philadelphia also made sufficient dies for its own use to
start the year, knowing they could always make more dies
during the year. It was during the year that the "Ts" broke, and only
after that the mint's "fix-it" was needed. Just my speculation here.
In 1949, San Francisco requested additional 1949-dated one cent dies. Monthly mintage figures released to the
ANA and printed in The Numismatist show a several month gap in San Francisco cent production while that mint struck foreign coinage, followed by a brief resumption of coining cents, with a mintage around 850,000. I
believe that those coins were struck with the later-supplied dies, but am not aware of any documents that could confirm this. What is known now is that Philadelphia took three dies with an initial 1949 hubbing and did the second hubbing with a 1948 hub,
apparently with the eight ground off. It makes no sense why this would have occurred earlier in the year, if a 1949-dated hub still existed. There is speculation that San Francisco's request came after Philadelphia destroyed the 1949-dated hub or that the 1949 hub failed or was damaged before the second hubbing. As with the 194[0]/1941 hubbings, the final product was a 194

/1949 die. Three versions are known, the 1949-S DDO-001, -002, and -003 coins. It would make sense why the mint did this in 1949 if the mint previously had done it in 1941, with no major concerns being expressed by anyone.
The 1943-S/1942
Lincoln Cent may also be intentionally doubled, but that discussion is a much bigger discussion and needs to involve the
DDO overdates from both World Wars.
Just a couple thoughts as I pondered this issue.