Simple knob for Delta shower that uses the ball style control (left and right for hot and cold, up and down for flow quantity). This is a picture of the mount profile:




Only intended to serve until a new part comes in the mail, but I included a step version in case anyone wants to remix it into something prettier. Be aware that the porous nature of 3D prints means it should probably be sealed to prevent anything growing on it if you intend to use it more than temporarily.

You'll need a longer screw to attach it. I found two walls and 20% infill worked fine in PLA. Doesn't get hot enough to be an issue, but for permanent use, I'd go with at least PETG.