When I wrote the Gas Pump Identification book (Revised) in 2008, I didn't have much info on the 48. One of the reasons was tha Tokheim somethings called the pumps 48s and the next time they called thm 486s. I tried my best to distinguish one from the other. I just looked and I don't even have a file for the 48, so it must be mentioned with some other pump and that is where I got the picture for the book.
From your description above, you have a commerciasl pump (not usuaslly used in service station) it was used in locations where it was not necessary to record the price of the gasoline sold. These were farms, cab garages, truck terminals, where they only wanted to know how many gallons were pumped into a car.
If it is all possible, how about posting as picture of your pump and I will try and identifhy it, in case it is not a 48.
I have posted over 5000 images on my website and many of them can be found in the Gas Pump Literature section, and if you have any questions, please feel free to email me if you have any questions. jhsim@swbell.net
I have both the Gas Pump Book and the Air Meter Identification book ready to ship, buth autographed by the writer. Email me if you are ingterested.
Jack Sim
Author, 1st & 2nd editions of Gas Pump ID book, 3rd edition is now available at
www.gaspumpbible.comAir Meter ID book also available