Couldn't find anything, but for what it sounds like what you want... here's an alternative: you can plumb in a push or pull clutch master cylinder in-line with your rear brake circuit... rig it up so an e-brake lever pushes or pulls on the clutch master... When you pull the lever it basically cuts the brake circuit in half as it seals, and continues to compress the rear fluid circuit as you pull the lever further.
Somebody posted it in my build thread on Pirate, if I didn't already have a t-case brake I'd consider it... seems pretty sweet!
http://www.pirate4x4.com/forum/showp...&postcount=214
