Natan is Hebrew and Noteh is a Yiddish name that is often used as an equivalent, either together with Natan or in place of it. Notke could therefore be a diminutive for someone named Natan or Noteh or both names together. An additional middle name following that is definitely possible.
I think in your case finding something else that confirms Eliash would be the biggest help. Eliash is much less common than other similar names like Elisha or Elya (a variant of Eliyahu/Elijah). If you can find other mentions of any of these names in your family it might get you closer to figuring out if your Natan Noteh is the same person.