One of the things I like to use heavily in mapping is the tools and techniques common in 1980s RPG graphic production, and in particular FORMATT-style drafting acetates. I have several sheets of these I rescued from a sellout sale at a drafting supply shop in Austin, but I haven't seen any others since, and it's a topic too old for the World Wide Web to have ever taken much notice.

So, on the hope (assumption) that I can't be the only one here grooving on 80's style RPG mapping: anyone else know of any good sources for old drafting acetate patterns?