I made the decision to refinish the wood instead of paint the floors based on the fact that they had turned out satisfactory after sanding. They also look quite rustic and have old house character. I did not use stain on this floor. I used shellac for the color and then applied two coats of polyurethane over the shellac except on some of the divots I have had to apply 4 or 5 coats of poly in order to reduce the chance of some areas splintering. The build up of poly on the rough edges of the splinters reduces the roughness of the wood on these edges. Another thing that gives the floor character are the plugs I made for where the floor boxes were:
I couldn't match the wood since I don't have any scraps from this floor and you don't know what color they will turn out until you put shellac on them. I will be mounting external boxes onto the baseboards and the wires should be hidden by the shoe molding. I have to paint the baseboards first, though.
Here is how the adjacent room turned out after a coat of oil based KILLZ primer:
Now for the big clean up. There is a lot of dust in this house!