I am looking for information on Doug Dutra's lower control arm travel limiter. How does it work and where can it be purchased?

I'm not sure if I understand what "travel limiter" means.
I have made-up special inserts that keeps the LCA "pin" from slipping-out of poly bushings.
Here is a photo link:
http://www.dutra.org/pictures/parts/dutra-disc-lca.jpg
DD

The travel I am referenced is the fore and aft motion of the control arm. So does the shoulder on the disk bear against the bushing shell or something else?

The Disc seats on a large shoulder inside the torsion bar / control arm bushing socket. With the disc installed there is no chance of fore/aft movement of the control arm on the pin.
DD