Using your chisels, cut along the scribe line.

Another view.

Using a razor sharp chisel, carefully remove the layer of wood.

The hole with the first layer of wood removed.

The side plate in the mortise. It still needs to go deeper.

Use the chisel again to remove the next layer of wood.

We are deep enough.

File the brass and wood smooth.

The finished piece.

Another view.

The trigger guard is done the same way.

The toe plate as well.

Another view.

Another view.

The Leman trigger guard is screwed on.

The Deringer trigger guard is pinned on.

The pin.

The Deringer side plate.

The Deringer side plate, trigger pin and trigger guard pin.