Yep you found MD. Mechanical or machne doubling. It is flat and shelf like. MD can happen anywhere on the coin, even on an individual device or letter.
It looks a lot like Wexler WDDO-003. You’ll have to weigh the coin, but this listing doesn’t distinguish between large or small date, or between copper and zinc. But I think I’m gonna have to side with @Pickin and Grinin and say MD. There is something with the top left Y that has me leaning that way. I suppose in-hand would be better to assess.
That one clearly has extra thickness. strong separation lines and notching. The doubling also doesn't wrap around the devices like the OP's coin.
Nice photos. Thanks for the post, but as mentioned, just MD, or what is considered "Worthless Doubling." See: http://www.doubleddie.com/144801.html In case you haven't already been welcomed to the forum; Welcome to CT David.
Here is a chart about doubled dies! I got it from one of the many posts it showed up on! I found it to be very helpful and hope you do too!!!