Need help before purchasing a 1995 Runner (transfer case)

Considering the purchase of a 2nd Gen (1995) with 221K on it, Motor is fine and just had heads shaved and head gaskets, radiator, all new wires and belts. It has been sitting a while. My main concern by far is the inability to get the transfer case in HIGH, Seems to be locked out of HIGH. Secondary concern is heavy white smoke. It was mentioned as possibly having water still sitting in the catalytic converter ahead of the muffler.

What is involved if I have to repair or replace the transfer case? How special were the nice aluminum wheels that appear to be original on the "Runner".

Lastly how do you reduce the idol speed since putting the engine back together?

Your help is appreciated and the sooner the better as others may beat me to the purchase.