Antique School Slate with Unusually Narrow Frame and Unusually Jointed Cornes irregular Unsigned and undated but I

Unsigned and undated but I believe dating to the 1970s

the wood is unfinished and shows some darkening in spots

There is one noticeable chip on at the rim nearish to the handle

no looseness or wobbling

Antique School Slate with Unusually Narrow Frame and Unusually Jointed Cornes irregular Unsigned and undated but II consider myself something of a connoisseur of antique school slates at this point, having bought and sold a whole lot of them, and looked at many many more. This one, found in southwest New Hampshire, sold me for the unusual narrowness of the frame, and for its unusual and very sweet notched corner joints. Also, there is a layer of what appears to be iron in between the two layers of the frame. Someone more knowledgable than me can surely understand