AC pulley in 1990 300TE

[crs82]

Finally cranked the TE up after about 3 years of sitting. Bad idea to let it sit...but had no alternative at the time.
Engine purred like a kitten except that it appears that the AC pulley was not cooperating with the rest of the crew. The belt was just skidding over it and I shut it down quickly enough that there appears to be no harm done to the belt.
My question is this: If the clutch on the pulley is bad, would the pulley spin freely or would it be frozen up? Am I likely just looking at a new compressor, or could there be a possibility of changing out the clutch and calling it a day?
When the car was parked, the AC did its job well (sound like a CL ad, now), so I would hate to have to open the system and fiddle with all of it.