Mark and chisel, mark and chisel etc.etc. A time consuming but rewarding endeavor. After making an outline of my side plate and an initial shallow cut, I then blacken the plate over a candle and then fit it in the mortise and tap it gently to indicate the high spots which are then carved out. Repeating several times until the plate is inlet for half of its thickness..........DanielAttachment 34672Attachment 34673Attachment 34674Attachment 34675Attachment 34676