Thank you all for the reference pics and comparisons. The differences are much more apparent. My main concern was pick-up-able functionality. I have a fileset of pretty darn accurate 3D-printing files. Comparing them now against the reference here, it's more accurate than I realized. But it's solid and static. The main thing the Nerf has going for it is a rack-able breech and opening top plate. I hadn't seen any replicas or 3D models that incorporate that. If I missed any that have moving parts, do please point me at them? *lol*
I think I am going to get one of the Nerfs through GameStop, so I can make payments over time. I like to have accurized pieces that aren't fragile, and that have interactivity, for convention tables. The barrel and stock are easily replaceable with 3D-printed pieces. The receiver... I'll have to see, once I have it in-hand and disassembled, whether I can maybe tweak any of the dimensions that still need it, depending on the final product.