After speaking with that one uncle and confirming my identity, I now have contact with my other three uncles. They all seem very happy to be speaking with me again. I even found out some stuff about my dad that I had no idea about, and am trying to find out if my grandmother had any photos in her assets that I could have.

That's fantastic. I'm delighted for you and your family. Hopefully you find some photos and piece together more about your Dad and his side of the family.