Not sure anyone here will know this brand, you might get lucky and someone remembers it, hopefully! If you are curious and want to dig more, there are newspaper archive websites that go back to the 1930s. I've used newspaper.com before and found maybe 10 ads related to "golden eagle gasoline". If the key terms are uncommon enough, like "blackhawk gasoline" or "blackhawk gas station" probably is, might get some hits from gas station adds in old newspapers without it being overwhelming. They may have their logo in the ad. Takes a little time to get used to how there database works, but not too hard. If I remember correctly its organized by states or regions. Newspaper.com has a one week free sign up and gets really expensive after that, so make sure you cancel your subscription!!! Probably take you an hour or two of searching.
Anyway just an FYI.