Why not line lock? (honest question)
I have no direct experience with them but I've read it's not good to have pressure on the caliper seals for extended periods of time. I really do need a good parking brake solution since I had to ditch the factory setup when I mounted my coilovers behind the axle - just no room whatsoever for the mechanism. I never had good luck with the factory parking brake setup on my 80, even after trying to adjust it. Not a fan of the stock setup.
Can you make us a tcase parking brake setup?? Here's one for the FJ60s. Can't imagine it would be that much more complicated for an 80:
FJ-60 TRANSFER CASE
FJ-60 Split Transfer Case Parking Brake kit includes: bracket, bolts, stainless rotor, and mechanical caliper. Rotor Bolt Spacing 2.6 x 2.6 and 2.36 x 2.695 Part# 4066MB3 $299.95ea.
www.tsmmfg.net