You can buy some NOS or repro stuff here:
http://ourworld.compuserve.com/homep...YDS/decals.htm

I used this stuff here and printed them up on my computer to do a custom paint job:
http://www.paper-paper.com/super1.html

The only problem with printing them yourself is that you can't print white, silver, or gold without a very special printer. But otherwise, it works really well. Here's one I did:
http://groups.msn.com/BicyclingForum...o&PhotoID=5701
http://groups.msn.com/BicyclingForum...o&PhotoID=5699