It appears the H-23 is a hand operated pump. My Gas Pump book shows the H-22 which is the air operated pump. It is on page 117.
I would say the picture in my book looks very much like your picture, your pump just has a handle. If you supply a picture of the pump with the cylinder attached and the bonnet on the pump, this will help in identifying the pump.

I do have a copy of the small sales piece of literature available, basically it shows your pump but without the handle. It is the same picture as in my books.

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