You haven't given us much information. How about an address for the company, any information about the company that might be on those plates? You would be supprised how much you can find from such little info.
This is what I did to find much of the information about the small gas pump companies I have in my Gas Pump Identification book.
I wrote a letter requesting any information about the company. I sent one to the Main Library, (name of town, state and zip). I requested they look up the company for me in the city directories. If you have any dates on any of the stuff you have, you should include them to help the people at the library so they don't have to go through all the directories. City directories usually include the name of the president and other officers of the company. Then you can go to the phone directories on the web and look up people with the same last names in those towns and call them and ask they if they are related to the people who owned the company back in ???.
The other letter I sent to the Mayor of the city with a cover letter requesting he give the letter to the person who was the town historian. Every town has a historian, it is usually someone who does it as a hobby.
Now keep in mind, people don't work for grins, expect them to request you send a payment to them before they begin going through tons of files. I had to pay many libraries for their work, and they don't usually work for less than $35.00 per hour or research. This type of research is usually given to a high school student that hangs around the library. It helps him learn something and gives him some money for his time.
This is why when guys request me to find some information on a piece of garage equipment, and I tell them to send me some money first, I usually don't hear from them again. I could spend days finding something and they expect me to give it to them.
One more thing, be sure to send them your email address, it is much easier for them to work through email than through the PO.
You might get lucky and find someone on this site who lives near the town and maybe they could look up some info. for you, but don't count on it, I tried and it didn't work.
Jack Sim
Author, Gas Pump Identification book and Air Meter Identification book, both ready for order at:
www.petrolianacollectibles.com