The gravestone is just for him...his wife later remarried and is buried elsewhere. Very good reminder about certain gravestones not being erected until years later, though. Honestly, I'd never even thought of that.
Yes, he was born in Poland. According to the 1910 census, he immigrated in 1909. The 1920 census says 1911. His 1929 obituary states he was a resident of Perry for 20 years, which matches with the 1910 census. However, I have not found him on any passenger lists (via searches on ancestry, ellis island and castle garden); I assume because there are so many variations of his polish surname. My search has been quite difficult to say the least.
I suppose now I need to figure out how to narrow down his arrival and how to obtain his immigration record...Thanks for all the GREAT advice, memesbaby57! You have been a tremendous help!