This question sent me to the file cabinets, looking for dates and brochures. It has also caused me to make a revision in my soon to be printed, Gas Pump Identification book. I have until next Monday to get any revisions to the publisher. No matter how careful you are, nothing can be perfect.
In 1934 the only Bennett pumps that were introduced were the Cash Computer pumps. Notice the use of the word computer, but not the computer I believe you are referring to. 1935 saw the introduction of the 135 "Station Master" series (135, 145, 155, 165). For picture of this pump and the Cash Computer face go to:
http://www.crspub.com/gaspumps/POM_June97.htm These pumps also used the Cash Computer meter. In 1936 some of these pumps were offered with the computer as we know it. This narrows thing down to the 76-77 series. It appears that the first Bennett computer pump was the Model 76 (two ad panels) and the 76-F (four ad panels)both introduced in 1935. Around 1935 the pump industry changed the definition of the word "Clock." At this time it now meant a "Non-Computing" pump, meaning it registered gallons only. The 77 and the 77-F were non-computing pumps (meaning they had clock faces). Early versions (1935) of the 76 had outside sight gauges, by 1936 the sight gauge was moved to the face, with no change in the model number. Thanks for making me look a little closer at some conclusions I previously made.