That's a cool survivor! Great seat on it too. Looks like it has glue-on 28" tires, these were last offered around 1937, so it's at least that old! It does look like a Westfield chain ring, though I'm not aware of them having any involvement with Excelsior, which was it's own brand into the early '30s. I believe Schwinn bought the rights to the name, but the Snyder co. bought the Excelsior factory in Michigan City, IN. I'd expect that to be listed for at least $750.