Who was Ralph's father

I'm continuing to work on chromosome mapping using matches to my Dad's results on MyHeritage and FamilyTreeDNA. One match I'm struggling with is named Ralph. This match shares 64.7 cM across four segments with my Dad, so potentially this is a good match to see where he fits, and to see if the connection is on Dad's maternal or paternal side.

When I look a little closer, I can see this tester died in 2020. He left a small tree, only with names on his maternal side, and lots of unknowns on his paternal side. Because Ralph's mother was a daughter of German immigrants, I feel like the common ancestor is on Ralph's paternal side. Ralph was born in 1933. His mother married in September 1937 in Cleveland, and the marriage record states this was her first marriage. A profile for the mother on FamilySearch also states that Ralph was adopted by the man that the mother married in 1937. The adoptive father was a child of Hungarian immigrants. The common ancestor has to be on a branch of Ralph's mystery biological father.

Ralph does have a second cousin match with 271 cM in common, also matching my Dad at 26 cM across 1 segment. There's more to do digging into shared matches of matches. Right now I'm parking this to pick up later, and moving on to another match to my Dad in the same range.