New to CPF! mod decisionsss.

Hey what's up bros im new to the forum and indeed loving it. since i was a little kid i've always been collecting lights and tinkering with them and am an avid hunter fisher and outdoorsman so lights have been around me all my life so with that aside lets talk about what im lookin at. I have an extra older 3D mag sitting in my room collecting dust among my 3 watt 2D mag and my surefire 6P and 9P and i've been looking through your forums but i can't seem to find a solid build for the 3D only 2 and 4D so any help would be fabulous and i've been pondering at an old rayovac standard plastic 2D yellow duty light sitting in my closet thinking of what i could possibly do to that also thanks guys glad to be on the forum!