1920's Service station oil pump

I picked this from a guy here in AZ who said that it belonged to his father and it was a service station's oil pump that would sit next to a clear glass gas pump. It is well preserved with oil all over the place. It looks like it may be yellow paint under all that. Still has oil in it and work very well. The rubber hose is original and in great shape as it was stored indoors. It has a cast iron base and probably holds about 3 gallons. I can't find any info on it and would love to know what I have. Any info would be sweet!

Thanks!