People seem to like the Ubersaw, so here, in brief, is how I made it:
1) Since I lack the proper woodworking tools, I used craft foam (white) and sheet plastic (black). Layers overlap for stability.
2) All the layers are glued together with a hot glue gun. Then, the saw is smoothed (not pictured) with Bondo spot/glazing putty and gesso.
3) Base paint job using primer, followed by spray enamels.
4) Beginnings of weathering job using Testor's model enamel paints -- black for grime, copper for the sharpened edge of the blade, and silver for dings and scratches in the handle.
The syringe is made from two plastic bottles. The inner bottle has been spray-painted red on the inside. The edges of the outer bottle have been cleaned up using strips of plastic (later replaced by thick cardboard).
The syringe is actually a bit small compared to the in-game saw, but I think this gets the point across well enough, har, har.
5) Everything assembled with needle made from a plastic straw. Blood was red acrylics atop of Mod-Podge for a 3D look, though I plan to use different paint next time for a more realistic effect. Finally, everything clear-coated with matte shellac. Tacks and a pair of rubber feet were used as rivets/screws.
Overall, this was a 2-day project. Not difficult, just tedious to cutout and wait for things to dry.