The ID cards are available again in the reprint: Supplements 1-13, The Classic Supplements published by Far Future Enterprises and available at RPG Realms.

I've scanned the ID cards at two resolutions: 200 dpi and 600 dpi. Whatever you use to print them, you'll want to adjust the scaling so the cards are 2 1/8" x 3 1/2" (54 mm x 89 mm) to match the original card size. I found that printing them out on check safety paper makes them look much more realistic. This is available in various colors and patterns from paper and office supply stores. I simply asked for some samples and was given a page of each color, which was all I needed.

ID Cards, Sheet 1, 200 dpi ID Cards, Sheet 1, 600 dpi
ID Cards, Sheet 2, 200 dpi ID Cards, Sheet 2, 600 dpi
ID Cards, Sheet 3, 200 dpi ID Cards, Sheet 3, 600 dpi