From the first day affidavit.
"It must have been about 2' long, and the top of the sack was sort of folded up, and the rest of the sack had been kind of folded under."
Whatever your interpretation of his description, can you provide any image of the bag known as CE 142 that could match it?

I assume the lighter paper is the top flap that closes over the open end of the makeshift bag.
If the bag is folded as Frazier reports - top flap closed and part of the bag folded under - it is clearly not long enough to hold a rifle, assembled or not.
If the bottom part of the bag is folded at the closest crease to the bottom, the bag appears, from some very rough measurements I've just done, to be the perfect length to carry a set of the curtain rods found in the Paine garage.