I used a 4-way leaf-switch knockoff that I got in a bulk deal for mine.
It had the really small size (Defender/Joust/Moon Patrol) knob on it, but had a long stick.
I cut a corner off it, routed a slot into the CP intead of the usual hole for the stick and bottom mounted the stick so the knob stuck up the perfect height for me.
I don't know if the dimensions are "accurate" to a true Defender panel, but they are comfortable to me, and work well.
I think my Reverse button may be a little closer to the stick than the original, but I never liked the reach the original anyway.