Auxiliary control valve Detent adjustment

[quadpa1911]

My A-B selector would not hold in position so I went to adjust the detent and guess what? When I loosened up the jam nut it broke free and dropped to the ground. The adjustment screw was broke and the paint was the only thing holding the jam nut in place.

My question is: Will the set screw for the adjustment back out for replacement (maybe enough to grab) or will the valve need to be replaced?

Thanks, Brian