Let us know the out come on this one -- I do remember the old 108's not liking water.
I believe that the regulator is in a different location -- did that get wet!
I also think that that car only has a 35amp unit -- so a belt that is a little off will really affect that car. The starter draws a lot of amps!
I do not drive my 108 cars very often -- but even when the cars were new the electrical systems were at the limit -- especially at night and in the rain -- in the summer with the AC
I can remember being on the highway driving home in the rain from the Jersey shore late at night and seeing that faint red glow of the alt light!