In this picture there is a 2"x3"x10" board that the Hanson scale has velcro under it just to keep it balanced on the 2"x3" but really the scale is held tight to the "EYE" bolt. The leather wrap is to keep the board on the rail and the board also has a 3/4" piece of oak 10" long glued under the 2x3x10 so it sits inside the rail.
You can see that 3/4" piece glued under in this pic.
The flouresent orange needle is just to show where the string loop starts as I crank on the winch and if I want to measure the string etc.
I also have a 1"x2"x6' piece of pine screwed under the Swanson Straight Edge and it can be removed easy just by lifting it out and the needle swings from left to right out of the way so the scale can slide as I crank the winch handle.