Friend of mine collects Commodores and related accessories. One of the keyboards he acquired was missing the fold out to elevate it. I broke out the calipers and replicated it in Fusion 360.

I printed it 3 walls, 20% infill, with PLA, .2 layer height 0.4 nozzle. I wouldn't go above a 0.4mm nozzle, so you don't lose the notches. Use an M2 screw at least 12mm in length to attach it. There are two versions. V1 and V2 have to do with the position of the finger groove. V2 has the higher version on bottom, makes it easier to flip up and down.

Mirror it in slicer for the opposite side