Nice thing about having a friend who's a dentist, I get free tools. Dental/cotton pliers (tweezers), dental picks (for scribing), spatulas for spreading fillers and grinding and polishing bits for my motor tools.

As for plastic cards, I collect all used prepaid phone and internet cards when the credits are used up. They are good substitute for styrene plastic cards.

While not plastic card i did make a descovery recently. If you know a cinema projectionist you could probably ask them for some scrap film that is otherwise thrown away. Every week we throw away bags of leader film which is used to label advertisment film etc.....well, this film can often come in all sorts of colour.....blue, yellow, back, clear etc. The great thing is that this stuff is perfect for using behind cockpit panels as a free alternative to buying detail film. It works in the same way too....you can scratch one side to create a clear line onto which you can paint white to represent a dial.