Krystal Princess Dome Leak

[garagesailor]

Hi all! I acquired a couple of these dolls, but after having them in a plastic bag, I noticed it was slightly damp inside, like one had probably leaked. Actually, the water level in most of them looks  a little bit low. So I guess I was just wondering if it is common for these to leak? I know they are 20 years old, but the plastic looks intact. My concern is with selling them I guess. Thanks for your help!