Henry in MI seems to be on the right track generally. The thought of trying to strip an entire floor makes me cringe. I have found that sanded and refinished antique floors look great! They maintain tons of "character". The trick is to try not to take off a ton of thickness, just enough to get through the finish and surface dings. If you do sand it then I would recommend a product from minwax that I have had great results with. I put pine floors in my own house before I moved in and my biggest concern was getting an even finish. I don't like when pine floors end up all blotchy from uneven stain penetration. This can look pretty bad in soft wood floors and furniture. When a floor is blotchy people look at it and think "stained pine", not "nice wood floor". The product is Minwax's "Wood Conditioner". It has very good instructions on it and it appears to be an oil/solvent mix of some sort. You are supposed to apply it to soft woods and then apply the stain within something like 40 minutes (before it dries). It seems to be absorbed more by the softer grained areas than by the tighter grained areas. This is what would cause dark spots if the actual stain was absorbed into these areas. The results are a much more even appearance. I have found, however that you need to use a much darker stain that you would have without the wood conditioner because less of it is going to actually end up penetrating into the wood. Testing on samples is a must to know what to use ahead of time. I used a 1/2 and 1/2 mix of dark walnut and cherry or red mohogany (minwax). It gave me a nice medium brown, not too dark. The uneven staining issue is probably less important with an antique floor since the wood grain was generally tighter back then than the crap pine we get now. It is probably a non-issue if you have vertical grain or southern yellow pine floors. Don't be afraid to sand your floors.