My windows also have Wavy Glass in certian spots. I guess it means that its old then. which this house is when I think about it. You're not allowed to replace windows etc
If you are not allowed to replace windows (please NEVER DO!!!!) then it is indeed very old. Wavy Glass is a sure sign of age. Its amusing what they build windows out of today, Vinyl and Plastic.
Wooden Windows are good forever whereas the pieces of crap that find their way on houses today need to constantly be replaced. These windows, some which are 12-16 feet tall, are as good as the day they were put in.