So I drug out my trusty T2 that also lacks control panel illumination and studied the control box looking for a way to mount the same type of flexible flashlight on it. I came up with a unique bracket that snaps in place and is very secure.
I will be refining the design to look better. Keep your eye out for this in the detectingdoodad store. It will be the same low price ($14) and include the light, battery and bracket in your choice of 16 different colors.