Joy
this is your ancestor in
http://ssdi.rootsweb.com LEO CHECK 24 Dec 1900 Oct 1983 23185 (Williamsburg, James City, VA) 23185 (Williamsburg, James City, VA) 708-09-8536 Long-time or retired railroad workers SS-5 Letter
His SS-5Form should have his place of birth and parents names.
Maybe he was born in vicinity of city of Gdansk and not in the city. You might want to search for his draft registration form, naturalization intent and petition, arrival manifest, state marriage application and church marriage record to confirm his place of birth so you can proceed further with the research.