Yeah, i think its a cobblejob, personally.
Mostley clone with a few gen ETA pieces on it.
Also , and this is NOT confirmed , but when i usually see the "DM" code on the plate, i usually see some sort of date code to the left of the balance wheel, which i do not see on the OPs movement. Ive seen them with date codes and no "DM" but never the other way around.
Also the gen units which ive seen come with the incabloc (from the factory) have always had the longer pallet bridge,
as shown on the furthest right hand of this pic. OPs apppears to have short (novodiac) style still in place.