With the sight glass above the face, this is an earlier model in the Bowser 500 series. Certainly worth restoring. Parts are available. Click on "Parts" in the horizontal menu near the top of this page.
If you are asking what gas brand it was, the green paint is a good clue. Phillips 66 used a lot of Bowser 500 series gas pumps. Their diesel pumps were green in that time period.
Here are a few other brands using green color schemes during that time.
AMOCO Benzol
Associated, Flying A, Tydol
Hickock Speed-ee
Kyso Super Crown Extra
Shamrock
Sinclair Dino (white side panels)
Texaco Diesel
Wilshire Polly
