Illuminaria, if I were to do it again I would get copper discs from Etsy.com.
Awesome 
This has me curious if there are any 2x18650 tube lights and or how difficult it would be to make an mtg2 heatsink well in a solarforce gladiator
I don’t know of any straight-up-tube lights (head is same diameter as body) that take 2x18650 or 2x18500. There are plenty of opportunities for custom work of course.
In my mind one of the most straightforward custom builds would be to make a head which attached to Solarforce extensions, similar to what dsche has done with his OrthoDogs project. Two 18650 extensions attached to a tailcap leaves space for 2x18700 with about 1 or 2 threads. That's no good, so either use shorter cells or switch to 4x123A extensions. 63.9mm vs 33.6mm of non-nesting tube, so you'd net an extra 6.6mm of battery space. Since there is 10mm or more of dead, unthreaded space on the front of an extension tube you would have that to play with as well as the 5+mm of threaded area that your pill screws into (depending on springs etc). With 15mm you could fit a lot of the light engine inside the head. 5mm for the driver area, between 12 and 20mm for the reflector, then another 1.5mm for the lens, then something to retain that stuff.
At that point you're talking about a pretty long tube light, but it's actually still shorter than a Streamlight Stinger.