I've never seen anything like it, and I go back to the Schluter Champion days, and have seen a lot of the really old kits going back to the original Kavan Jet Rangers, Dubro Whirly Birds etc. None of that old stuff had any detail resembling this.
It looks like some serious hobbyist built it custom, based on a real helicopter (the links and complex shapes). Where is the rest of the model? It must have been something.
Looks like a one-off, maybe a scale Alouette head?
I think it belongs in a model museum, especially if you can find the rest of it. Since the head is not damaged, the rest may be intact under a few inches of dust somewhere. Would be nice to get it all back together, go check the attic again !!