Who here knows old Cushman chucks?

I have an old Cushman chuck. It may have been made as long ago as

1899. I have emailed Cushman about this chuck, trying to date it, but haven't heard back from them. It is about 4.300 diameter and is made from cast iron. It looks like the chuck may have been nickel plated. The only evidence of any plating is on the back of the chuck. I'm not sure how to tell if what looks like a very thin, almost worn off, nickel plate is actually just burnished cast iron. Were Cushman chucks plated? Thanks, Eric