That sounds handy.
You can also mold small thermoplastic parts with a homemade injection molder. I made one using the clylinder and piston from a car shock absorber, an electric drill and threaded rod to inject it, and a hot-air paint stripper to melt the contents. The same device can also be used for doing extrusions, but that's even easier because you don't need to clamp a mold closed.
You can also use silicone rubber molds to duplicate other parts, but I didn't develop this idea very far and only got some distorted parts out of it.
For some shapes it's also possible to just leave some plastic sitting in a mold in the oven for a little while.
check this link
it basically shows how to melt syrofoam with paint thinners, you can then mould the plastic like playdough and then leave to harden.
it might be useful to someone...