Without a doubt, it's a vac-form "Heinkel He-112 B0" from Rareplane. I bought in my mit-teens, back in 1979, when I didn't know what a vac-form was (or a Money order, by the way). It's the only vac-form in my collection, and for the foreseeable future it'll remain that way.
If partially buildt counts, then the prize for injection-moulded goes to a "PT boat ELCO 77 feet" from Lindbergh (bought in 1980).
Regards to all, and have fun with this wonderful hobby.