Thanks for the info. I just noticed there an embossed profile of a Spartan in brass on the 'buttstock'.
After looking at it for a while, it appears as though your arm goes through the big hole, and if you can see, there is what looks like a trigger guard painted battleship grey towards the front.
Furthermore, the entire front of the arm was fashioned in the general likeness of an M1911A1 or (?) a VIS? Very interesting, and odd. . .
Edit: my take on the ironmongery hanging off the front could have been to improve the balance, AND the shroud apeared to be their way of addressing sights. If you were going to go through the trouble of making a 1940's bullpup, you would want to ensure that it balanced perfectly so you could swing it like greased lightning.
Then again it could have been something a bored kid cobbled together.