Do it yourself

Hi All, My wife and I are remodeling an 100+ year old farmhouse. The woodwork is what gives the interior of the house it's uniqueness, so we are restoring the doors, trim, etc. rather than replacing them. The windows in the house are about 28" wide and 60" high. They are typical vertical sliding wood windows. I would like to restore them just like the rest of the woodwork in the house. Most of them have never been painted on the inside, just the original stain and varnish is there. Most of them work fine, except the ropes for the counterbalancing weights in the walls need to be replaced in many cases. I think I can handle refinishing and reglazing these windows. My concern is, how can I make these windows reasonably weathertight? I can live without double-paned thermal glass and all that, but I need to keep them from being drafty. Is it possible to buy weatherstripping that can be installed in the small gaps between the wood frames? Am I crazy for even considering keeping these old windows? Thanks, Mark