I have a Tokhiem 36B pump. The repair parts manual that is widely available, applies to pumps beginning with serial number 788200.
My pump number is 751577. What does that mean if anything?

I don't know what you are using for a reference, but your pumps was made sometime in 1936, no information as to the month.

If you are looking for information about your pump, go to this page of my website and click on 36B: http://petrolianacollectibles.com/tokheim%20pumps.htm

Jack Sim

It may mean there's an earlier manual available... My 36B manual applies to pumps beginning with serial number 750,000 and up.