This piece is likely from the early 1900's, and it is a beautiful example of making a utilitarian object be aesthetically pleasing as well. The grate is Cast Iron with a copper finish, the backing for the thermometer as well as the side pieces aren't magnetic, so they likely are copper.
I see no damage to the grate, but the side trim is misshapen and bent in several spots. Please view all 12 photos to help judge condition.
The item "Rare Antique Ornate Cast Iron Thermometer Grate Case Powers Regulator Co Chicago" is in sale since Monday, May 29, 2017. This item is in the category "Antiques\Architectural & Garden\Other Antique Architectural".The seller is "matteov772012" and is located in North Haven, Connecticut. This item can be shipped to United States.