Hi Ben,
Welcome to Oldgas.com Shop Talk,
Always great to have younger enthusiasts in the hobby.
I love old gas pumps and 1960s Mustangs myself.
Your family history has to make this extra special.
Look on the side of your pump for an ID tag. Should have a stamped number on it. I think the 595 differs from the 585 by how the hose retracts or not? Photos of the hose side might help if you don't have an ID tag.
Click for photo of an older but similar
Bowser 565 in Phillips 66 colors.