Worked on the "down" stop first. Initial measurement of travel using a digital level indicated I needed a couple more degrees travel. Did some filing of the lower horn and got the travel, but the horn would catch on the edge of the fin mounting bracket. Riveted a piece of scrap .063 plate to provide a positive stop for the lower horn and prevent catching on the edge.
Positioned the elevator at 28 degrees up and measured where the stop material needed to be cut. Used a cut-off wheel to cut the material and drilled pilot holes. Positioned and clamped material and after final checking the angle, step drilled holes to final size. Deburred and riveted with AS5 rivets. Not sure I like the stop hitting the thin top skin directly. I may add a reinforcing strike plate later.