A Little Fun...animated Overlay

You are a constant source of amazement.

These are fun--I've played with these animations in photoshop.
I like to play with the delay between images to see what's easiest to see.

I specialize in overdates, but I haven't studied the possibility of an 1958/1957 (since it technically would involve two hubs)
I guess you haven't seen much evidence supporting an overdate? Personally, I don't see much that's conclusive--all my overdates have stronger markers.

Were Lincolns done with the Master Die having a 19xx date, with the final two digits punched into the working hubs, or did the Master have the entire date? I could see the massive production rates requiring a new Master each year, but I don't know how many working hubs a single Master could produce, or how many working dies could come from a single hub.

Creating a new Master Die from a previous working hub doesn't make sense - it's rather unprofessional and implies poor preparation within a system they had down pat - producing Lincoln Cents - decades earlier. I'd think there would be some little degradation of the details if done that way, as well.

1956 and 1957 were the first two years Lincolns reached the mintage level of 1 billion since 1945; I could envision a surfeit of 1957 working hubs since they'd have had the order from Congress in plenty of time to produce a large quantity of them at the beginning of the mintage year. And Denver had been carrying the heaviest load of Lincoln production throughout the decade of the 50's; I would think they'd have efficiencies figured out.

I'm seeing an overdate there. Are they common-enough to be explained by a single working hub? That's still a lot of coins from multiple dies. Can't see the Master being the culprit, or they'd all show the feature more or less.

You did a good job alighing two dates for the animation! That's key in getting a smooth transition.
OK, I admit that I see something in the 8, and that it follows the contour of the 7, but I'm unsure if that's enough to get my curiosity.
Even within the realm of US overdates, there is usually more remaining digit, particularly inside the 8.
One of the subtlest US overdates, the 1858/7 Flying Eagle cent, has a corner of the 7 showing far outside the 8.
Often the corners of digits show in overdates, because pressure is focused there when the die was made.
--just some impressions from looking at overdates

See if you get similar alignments from different 50's years.

Looks pretty good! You can see the ear, back of head and neck, truncation of bust, and a little of the crown.

Very Interesting Post on the 1958/7 Lincoln Cent that Breen described. Almost all proposed 1958/7 Lincolns are just die gouges through the "8" and mostly through the upper loupe of the "8".

I have one example that is hard to explain away where the lower portion of the a "7" can be seen below then lower loop of the "8". This die also has two identifying modifications - 1.) Die clash in front of Lincoln's Throat and, 2.) a small die crack from the top of Lincoln's head out to the rim. That's something you can look for.

I will take some images and post them here soon.