Leaf spring identification help

I have consulted search and the google, but no answer.

I picked up a set of used 3"-ish leaf springs but they need a set of new bushings so I want to order the right ones. The only markings on them are "RK00101" and "USA". I looked on the Rock Krawler web site because of the "RK", but I didn't see any full leaf springs. Does anyone know who might have made them?

Anybody?

Here are some pictures.

It may be an old Rock Krawler part number call them direct to find out if it is or not

For future google reference, These leaf springs are the only Rock Krawler complete leaf packs they ever made with their name on it. They still make the bushings. Nice guys on the phone too.