keaton vintage american bulldog cap gun 1920's

This is a cast iron toy pistol made by Keaton. It is called the American Bulldog model. Everything works on it as it should. The barrel breaks open to load and it will cock and shoot when trigger is pulled. It does have some surface rust as can be seen in the pictures. From what I can find out about is that it was manufactured in the 1920's. I can't be sure of this so you can research it for sure, I am no expert on these. Thank you for looking.