Approimately 12 x 16 with wooden frame (2"), old nails, old wire and dirty from over 20 years in an attic of the estate of Carol Holladay Hyatt wealthy people from N.Y. Micigan and Palm Beach.. On a panel, never removed from frame. Surface is hard to determine.
bought he land and summer cottage and contents came with it and old owners were deceased and Harvard U did not want contents nor inventory, sold turn key untouched for many years.