I made a few of these trapped wedge marking gauges some time ago from an article in Popular Woodworking.
I like the one handed action of these and one can never have too many marking gauges. I added extra arms for this one and set them up as fixed mortising gauges, one for each of my mortise chisels.
Today, while the guy from the overhead door place was repairing my garage door opener, I messed around in the shop and added another arm, a shorter one. I cut a saw kerf in the end and drilled a hole at the end of the saw kerf to prevent splitting. I drilled a clearance hole through one side of the kerf and countersunk it, then drilled a smaller hole in which to screw a 5/8" #8 square drive wood screw. It can now be used as a scratch bead holder for cutting beads and the like. The screw squeezes the kerf to snuggly hold the scratch bead.
Tried it out on some scrap pecan and it worked great, although I can't see the results in the pictures I took, so . . .