Not sure if this is the article that "gmoody" was thinking of, but in the April 2000 issue of 4Wheel & Off-Road, there is a pretty good article pertaining to the NP 205 T-case among others. According to the article, it can be found in the following vehicles:
'69-'73 Blazers and Jimmys w/ auto trans.
'73-'74 Jimmys w/ auto trans
'70-'73 GMC pickups and Suburbans
'75-'79 GMC and Chevy pickups w/ manual trans
'81-87 Chevy and GMC K3500 pickups
'69-'74 Dodge Power Wagons
'80-'84 Power Wagon W200s, W250s and W300s
'76-79 Ford F-150s & F-250s
'76 Int'l pickups (probably other years too, but this one I know first-hand) [img]/wwwthreads_images/icons/smile.gif[/img].
NP-205 has a low range of 1.96:1. Can be combined with part of a NP-203 to obtain the low range ratio of 3.96:1 (probably not adviseable in a CJ-5 however). Can be converted to a twin-stick setup fairly easily if so desired.
That info should give you a start as to where to look for one of these cast-iron beasts. Hope it helped a little bit!