You are making an assumption the all gas pumps were purchased by the oil companies. Many stations were owned by an individual and he purchased he pumps from the local petroleum equipment company closest to where he was located. The petroleum equipment companies usually carried one pump companies products. Many small filling stations purchased used/rebuilt pumps.
Over the years some oil companies got affiliated with one or more pump companies. Sinclair purchased many Bennett pumps for the stations that Sinclair owned and were operated by dealers. Standard Oil had a close affiliation with Gilbert & Barker, even investing in G&B.
Big oil companies were divided into zones, and each zone could choose which company they were going to purchase their pump from.
In the late 1990's I received a call from the Bennett Pump Co. in Muskegon, MI. They had been purchased by some local men and were moving from the old plant to an new location. I was allowed to acquire much of their literature. One of the things was a box of over 500 onion page type blueprints, going back to 1925. Each one of these show how to paint and decal pumps that were special ordered. These pumps were being purchased by different zones of the oil companies and the painting/decals were not the same, so there was no one and only way the oil companies wanted their pumps to look like.
Assuming you have a Tokheim 39. They used the 39 on a tall and three different short pumps. More information can be found on my website at:
http://petrolianacollectibles.com/gas%20pump%20literature.htmClick on Tokheim, then click on the 39 you have.
If you email me the information found on the ID tag, I will let you know the year and possibly the month your pump was made. Unfortunately it is not possible to determine who the pump was first sold to. Tokheim went bankrupt around 2002 and all their literature is being stored in Ft. Wayne and you would have to go through 1000s of records to find this information. My email is: jhsim@petrocollect.com
As for colors used on pumps Wayne Henderson/Scott Benjamin wrote a book covering this. (Somebody please post their email address, I can't find it).
I am the author of the Gas Pump Bible gas pump identification book, information about this pump can be found at:
www.gaspumpbible.comI am also a contributing editor for the magazine "Check the Oil." Over the years I have written articles including a history of the Tokheim 39. Incidentally Tokheim made over 125,000 Model 30s. I suggest you subscribe to this magazine:
www.checktheoilmagazine.comJack Sim