I need to cut the mortise for the spline of the breadboard end. The end on the left was cut first with my router. I didn't like the way it came out, so I decide to cut the mortise on the other by hand. Unfortunately, I do not have a mortising chisel. I used my Irwin/Blue Marples paring chisels to cut the mortise on the right. The dimensions of the mortise on the left is 13/16" w x 18"l x 3/4" d. The mortise on the right is 13/16" x 4" x 1/2"d. Notice the difference in dimensions there? Yeah, took me 30 minutes to do the mortise on the right. I broke the Colt back out to finish it up. Well worth it.