I wish I had thought of that, I actually had enough wood, here is the scary finish, it's more like a space ship then a Grapple Gun, not sure if I wanna finish it with bondo now or not. I have a big square of 3millimeter thick ply from putting a secret panel in my desk draw, but it's a little to late, though I might use it for the main body and just fill it with foam, or expanding foam, or even leave it empty.
Oh, and if you get around to modeling it, I can pep it for unfolding and for wood/foam use.
Well, horror pictures now: