It is a G&B 86, This pump was introduced in 1936, G&B called it their "Calco-Meter."

It is shown on page 206 of my Gas Pump Bible book. www.gaspumpbible.com

There is also a number of pictures of this pump shown on my website: http://petrolianacollectibles.com/gilbarco%20pumps.htm

Click on the pictures for larger views.

I hope you have the top as it is missing in the picture.

Jack Sim

Author, 1st & 2nd editions of Gas Pump ID book, 3rd edition is now available at www.gaspumpbible.com
Air Meter ID book also available