Hey Cityboy!
I stumbled across Standard Transmission & Gear (www.standardtransmission.com) while surfing the web for rebuilt transfer case for a Jeep Grand Wagoneer (gas). They have rebuild kits & parts for the Getrag. Even they think the NV4500 is the way to go when it comes time to rebuild. Check them out!
I have never done business w/ these folks, just one source for the Getrag. 1-800-783-8726
1992 W250 5 spd. (Getrag w/145,000 miles) 3. 54 gears Banks "Stinger plus" kit consisting of a 14cm2 wastegated housing, 3 1/2" exhaust/ muffler, K&N, pyro/boost gages, 2 1/2" Skyjacker front suspension lift to clear 305/70R/16's