This was made pretty quickly, but I think it is a good idea. Plastic MUST not be completely melted, it only needs to be slighty plastic, otherwise it could fuse to the mold.

This has a good example of doing it: 

Instead of using "3D print waste" you could use the spool.

The third model is a press rather then two negatives. (EXPERIMENTAL)

Solemn, bless prusa, maybe this will win the comp.