Hello TANA.
I wonder, how did you bore the E head without dings or scratches?
Actually I already made Triple XP-G E1e but it has a lot of scratches while the head bores and body bores for 18mm.
Thank you.
If you have a VERY precise lathe (which I sure don't, for now), then one dedicated round bar threaded with Surefire threads (or some already make circular E series clone body) can hold your head while you bore it...
I use 2 or 3 layers of Kapton tape that I carefully chuck in lathe... once you have it centered, you go for it, small moves so it doesn't jump out of centar... that said, my first few heads did have few chuck marks, single thin line on every second hex, thanks to my "pro" machinist who did few for me... now I'm doing them myself and last two had no marks, thanks to Kapton thing...
As for bodies, I will never try boring as it seriously lowers durability but also authenticity of the body (I like being able to, with few things, to be able to return the host to stock level, these are Surefires afterall, in this case replacing head with empty E-series bezel and stock switch)...
Hope it helps... I'll try to make a video or at least few pics next time I have bezel that I work on...
Oh, you could make delrin or teflon adapter to hold the body in while in lathe while you widen it to 18,6mm... but still think it's too much stress for these little beauties...