...best to go shopping for new.

Even with a new unit the receptacle may be damaged and may still need to be replaced. Be sure the circuit can handle the amperage draw, compare the nameplate rating of the new unit and add up whatever else is on the circuit to be sure it doesn't exceed or come close the circuit rating, usually 15 amps. The grounding issue remains, unless the new unit is double insulated with a 2 prong plug, but I have never seen an appliance like that that is 2 prong.

...yeah, i sorta eluded to that earlier.

Good suggestion about checking for tarnish, Dave. The adapter prongs were heavily tarnished. I scoured them with some fine sandpaper until they looked their original golden color. I ran the conditioner for 2 hours and checked the plug - only slightly warm. Also, I put a block of wood under the unit to stabilize it and no more leaks. I think it's because the unit was tipping in that it was leaking. Maybe the window changed shape? I've noticed that the storm windows are much more difficult to get in the frame than they used to be and even when I close them, they look as if they are bulging out. This #$&@* house!