Finishes for antique heart pine
Polyurethane has been the standard for the past twenty years. Aluminum Oxide is replacing it, especially on pre-finished flooring, because it last longer and provides as good if not better protection with a thinner coat. But it also is not nearly as easy to apply. It sounds like it might be more of what you are looking for, but it will be more expensive to apply in home.
You also might want to consider using an penetrating oil finish, in addition to the polyurethane. I have used it under polyurethane, and it created a really supple, low-gloss, luminous finish. You need to use oil-based polyurethane if you do so, though, because water-based poly will not adhere to the oil finish.
[This message has been edited by Lawrence (edited April 15, 2003).]
Oil finish brings out the rich, warm amber tones of the heart pine. Putting a water based poly on it makes it lok like plastice which I am sure is not why you invested in this flooring.
For a reallly soft antique look, use a penmetratiing rubbing oil such as a Watco or Tung oil. This will be very time consuming though. It is easier to touch up again in the future