Just starting, well a little ways in, to restoring my 2/87 Bronco. I found it interesting that the early BW-1356 Transfer Cases have two fixed yokes. Instead of the more common one slip yoke and one fixed.

Early BW1356 No Slip Yoke

 

Yours is the more robust better style IMO
Your style would wear out the slip yoke splines on the rear driveline
That makes the truck grunt or shudder during takeoff from a stop after the splines get worn and the grease no longer works
The special teflon driveline grease was used to combat that grunt or clunk on takeoff
The newer style (with the slip yoke splines in the transfer case) was supposed to fix that, but they also need their splines greases as the transfer case ATF will attack any grease in the yoke over time
The new style ones also had a few TSB's about the special grease and an updated higher nickel content yoke with better spline quality
Lots of trouble with those newer ones for the grunting and take off shudder and the associated clunk
Your driveline should be good for 200k then have it rebuilt with new splines and a new slip yoke, new dual cardan etc

 

I got the transfer case disassemble. The oil pump stop has worn all the way thru. I found a company on ebay that make a modified oil pump retainer with an extended end that will function with a case like this. There is no hole or leaking, the case is functional but will need the modified op retainer.