Highest price would be for matching numbers on receiver, bolt and magazine. Also, highest price if all the various parts have matching maker stamps. If the rifle has been "FTR"'d (Factory Through Repair), many of the parts might no longer be of the same maker - that can also happen when someone starts putting bits and pieces together picked up at gun shows or wherever. From Wikipedia, there were about 80,000 of these made at BSA Shirley and about 160,000 at Fazakerely plants. So, for example, if it has Long Branch or Maltby parts in it, the price should be less than the top ends stated above.