First - let me say thank you so much for your advice & wisdom!
OK - Joseph married Anna Vrabel in upstate NY. Anna was born in Pennsylvania. Her parents were Ondrej Vrabel and Maria Kelechave (We have seen this name spelled many different ways - Kelecava, Kelecova, etc.) The Kelechave spelling I got from a church in PA where my grandmother was baptised. Absolutely no idea where they came from. Census records say both Hungary and Czechoslovakia. I know they spoke Slovak. The family is all Roman Catholic. Anna's parents never became citizens. Vrabel and all the variations of it, seems to be a popular name.
Using your suggestion, I did just tonight find a Jos Salwa on a passenger list in 1913 (Naturalization papers says he was in the US since Oct 20, 1912.) Not sure that this is grandpa but it's the closest I've seen.
Maybe he was trying to "hide" his Polish ethnicity? When my grandparents got married, it was in a Catholic church that was founded by Slovak immigrants. He became active in the church even though there was a Catholic Church founded by Polish immigrants down the street from our church. He never spoke of his past.