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
http://www.instructables.com/id/How-to-%22make%22-plastic/
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...