Hi,
I could be wrong but from the bottom plate, it looks like an G&B MIK pickup to me.
They produce most of the Epiphone pickups for Gibson, as well as alot of pickups in Fender
lineup (also Gretsch, example Fidelitron). It could also be real DiMarzio that someone
swapped the bottom plate to another pickup's. Maybe a picture of the front side of the
pickup might help in further indentification. What's the resistance rating of it?