https://en.wikipedia.org/wiki/Doubled_die Quote - "Note that the proper terminology for this occurrence includes the letter 'd' at the end of the first word, hence "doubled die". The term "double die" without the first word ending in 'd' is not proper numismatic terminology." closed quote
Doubled Die, no. Machine doubling, most probably. Kool to find, but there ain't much value associated with the find........just bragging rights that you found such an specimen. Shoot, I ain't found one yet........