As for dating pumps the best source is the Blue Book as long as the company was still in business (Fry wasn't).
Years ago while I was really researching gas pump companies I once talk to a woman whose's father owned a gas pump company. She told me that when they put the numbers in the "Serial" number they always started with 30,000, this way it would appear that the company had made many more pumps.
As soon as I get this damm gas pump book printed I was going to start a new project, I am and will be trying to accumulate as much information about the Fry 17/117/171 whatever pumps. I already have a large file of information. I will be asking the guys to send me a picture of the pump and what the original ID tag listed for the Serial Number. My goal will be to try and determine when all these changes were made.
Author, Gas Pump Identfication books 1st & 2nd Editions & Air Meter Identification books
We rebuild ECO air meters and sell parts.