Got the “butt” glued on. It’s a little rough around the edges, literal

Got the “butt” glued on. It’s a little rough around the edges, literally, but I’m hoping some putty, bondo, and sanding will sort that out nicely. Also building up the details on the back of the pack. Trying styrofoam core for the shape and then Sintra glued on top of that to give a nice hard surface. Might be tricky!