Q: One visitor asked, "My floors are not even due to settling of the house over the past 50 years, is it a problem refinishing them or would it be OK?"

A: A lot of older homes have uneven floors due to settling, mine included. Some are more severe than others. The main thing to consider is how much wear surface is left on your existing floors. The wear surface being the distance from the floor surface to the top edge of the groove. If it can tolerate another sanding, go for it!