Old working gas stove, 1920's?

Hi and Thank you in advance for your help.

 This is my grandmothers stove which I think she purchased in the 1920"s but I'm not sure.  Unfortunately my gram passed in July so I can't ask her when she bought it.  I know she bought it new and it still works great.  I am trying to find out approximately what this is worth and any other information you may know about it.  All I know is that It is a Caloric.  Thank you for your help