Hey folks,
I stumbled upon this today… and figured it might be a quick / cheap way to make some small moulds… not sure how well it’d work, but what the hell 
http://www.instructables.com/id/Make-a-good%2c-cheap%2c-upgradeable-sheet-plastic-vacu/
The guy who made the tutorial’s site is here… has some decent info on how to make some vacuum pumps on the cheap and what not:
http://www.vacuumformerplans.blogspot.com/