I made this mount so that I can attach a magnet to the base and have the flexibility to hold the flashlight in various angles to direct it where I'm working. I left the base open so that it could be attached to a clamp or mounted to a bench or magnet in my case.

Undersized the bolts width (not height) to 95%
Upsized the nuts width (not height) to 105% this helps aid in assembly with the threads.
Can print multiple arms to satisfy your application or for versatility.