It is going to take you more than following around looking for old service stations. They had a few items compared to the bulk plants that supplied items to service stations. My first large purchase was almost the entire contents of a bulk plant, including 100 gas pumps, globes, cases of unopened oil and grease cans, but.....this was back in the late 1980s.
The old stations are easy to find, just ride old small roads, most stations will be at junctions of two roads. If that is all you are looking for, just take your camera with you, , but if you are looking for gas pumps, etc. you will need to do some knocking on doors, particularly at farms. Many had pumps outside, but they were removed in the late 1990s because of the leaking tanks. The pumps are hopefully out in the barns.
Also ask questions, somebody might tell you of a place down the road that has something.
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