As I mentioned above, the pump is a tall 39 with a National top. National had become part of Tokheim in 1947 (for a small history of National see this page of my website: http://petrolianacollectibles.com/company_histories.htm
) . The date states 1948, but this is incorrect, it is 1947. No pumps that were being made by National prior to the acquacation were ever made again, what Tokheim did was just make the tall 39 but put a top on it that looked like the previous National pumps.
The inside of your pump is Tokheim 39. The faces are identical to the Tokheim faces, they just say National.
The 62 series National pumps mentioned above were short Tokheim 39, again with a National looking top. Also, the pumps were made in Ft. Wayne, not in Cincinnati, Ohio.
All the differences in the 39 are explained on this page of my website: http://petrolianacollectibles.com/tokheim%2039%20tall.htm
What applied to the Tokheim also included the National. Notice there were two different tall 39s.