Found this 1980 penny showing different types of doubling . Need more experienced eye's to educate me
I see MD and some wear damage, but no DD. A DD usually increases the width of a device such as a number or leg of a letter, adding both components ( not changing the main Die width and adding the doubled die widths together ( 1 + part ). But MD smashes down part and Decreases the width of the main part ( 1- part smashed). While the damaged part may have a minor effect of increasing the damaged portion, it is very small, Also a DD, both the original die squeeze and the misaligned die squeeze are usually close to the same height, ( as there were multiple die squeezing before the current single squeeze method) but with MD, it is not usually the same height or even close. Jim