I just bought a couple, here's some suppliers from a previous thread:
- PEP:
http://www.peparts.com
KT100-EB-BP
I got mine from here:
Mid America Motorworks ( Schroth Eyebolt part# 112-061)
I haven't got a seat mounted yet but the bolts fit perfectly (they're an unusual thread, M11-1.25 if memory serves...)
Mike