It would depend on the time of year. It maybe in a transition between fonts. I have a matching byf 41 which has all lower serif numbers.
In Jan Stills "Third Reich Lugers" on page 85 it shows a byf 41 # 4801 which has the same type of lower serif "1' as the pistol you are asking about. This pistol also has the trigger bar with a lower serif "1" which is different from the frame and other parts. I do not see this as being a non matching gun. If all other parts match then chances are this is a good luger.
Jerry
