in your first pic above, the vacumn lines go to the UFO looking piece, that is the vacumn actuator thingy.
the other are wires for sensors.
is the hole open into the transfer case? if it is there would be no oil left inside as it would just drain out.
Ah, noted. I will get back under here tomorrow to examine the condition of of the vacuum hoses now that I know where to look. I will also take a closer look at the hole in side of the t-case, but you confirmed my point of interest. If the hole is bored through the transfer case and was was not plugged, it would leak all of the oil out. So maybe its just an indention where a threaded full bore would be, maybe part of the casting. That adds up.
Thanks 3_puppies. I'll report back my findings!!