I just ordered some (literally 10 mins. ago) from
www.onlinemetals.com-From my confirmation email-
2 pieces @ $1.37/piece
Brass 260 H02
Sheet
PVC 1 side
0.51 mm (24 ga.)
Cut to: 1.5" x 6.5"
The nice thing is that they will cut your metal order to any size, should be able to form these around the forks with a strap wrench, I don't think you could do that easily with stainless. I plan on dabbing a little anti-seize between the layers just in case.
Upside- Custom cut shims in quantity 2 for less than three bucks
Downside- Shipping was $12.93