YAMAHA Decals & Emblems
 

This guy sells different sizes and colors. He sells them for Yamaha drum kits, but the font and the logo are the same. I've purchased a couple, and they're very nice. I put some 3" on my helmet, and got a 9" one also, but I haven't applied it yet. Here's the url:
http://www.ebay.com/itm/201588328917...%3AMEBIDX%3AIT
Hope this helps someone.
Jon