Possible Clues:

• Projection shaped to fit into mortise
• Piece of wood fitting into a mortice
• Shaped wood in joint
• Saw a number working
• Dovetail piece
• Projection shaped to fit into a mortise
• Piece to fit into mortise
• One sort of saw double figures on this
• Saw this with x over (or below) it
• Saw to it that there was a number on it