Thanks all for your kind responses! We had my brother-in-law, who is a contractor, look at the house and he was of the opinion that it was not that bad. There are two areas where the drywall would need to be removed (the windows did not have proper flashing) but other than that, it appears to be minor, if yucky, surface mold problem. We checked out the house again during some heavy rains and other than the windows, the house was as dry as a bone. If we find anything of interest later on, I will come back and update. Thanks again all!