1X18650 torch with a compatible extension tube/thread compatibilty Q

I was thinking of undertaking a little project soon. I was going to buy something like a convoy M1 or Roche equivalent and turn it into a right angle light by purchasing an extension tube, cutting a 45 deg miter, and welding it back together after a rotation. However, no one specs the thread types for their hosts, so I don’t quite know what to buy. So I”m hoping someone can suggest a light and an extension tube that will fit together. I’m not sure an extension for the tail cap end will work, also. I have some other ideas that involve frakensteining lights, so any tips would be welcome.

Solarforce lights can be bought with extension tubes. Not sure of any others though.