Boy, I got two F6's I'd love to have this done to... Looks really good, much better than my jammed in aluminum foil technique 
. Btw, I have an AA size tube for an F6 - they were available a while back on a AliExpress store here but look like they only have 18650 tubes remaining.It fits fine into the "new" Convoy F6's I have (no window).
Tiny endmills ordered. 0.055", 0.010" corner radius.Good thing I can spin my drill press up to 11K, huh?
Had to make a thing to make some other thing.
I'll have to run the indicator on the ID of that center hole, which should be lots of fun. The OD of the threaded sleeve fixture mount holder thing isn't round anymore after it gets squeezed closed in the chuck and there's no other good surface to work from.
I could send you two of the threaded brass plugs, then all you'd need to do is find a 53/64"-20 tap. (while searching for that tap, keep an eye out for a radiator cap for a '69 VW Beetle.)
But seriously, if you can get an accurate measurement of the size of the hole, I can make new plugs (AL or brass) sized to give the correct press fit. Or you can send me your bare tubes and I can thread 'em.
Tease (still very unfinished):
Your doing an RBD to me. As usual I have no idea whats going on but it looks good. 
Might take you up on the offer to send them to you. Not sure if you follow the 25/45/85 thread, but I got my parasitic drain down to 0.154 mA with a good chance of reducing it by a factor of 10 (0.015 mA). Those kind of improvements would be nice to have in this F6 light. The Ferrero-Rocher firmware doesn't shut down the AtoD during sleep, so the parasitic drain is about double.
In my 85 firmware, I also have a lock-out feature done by 2 quick clicks and a click&hold. Blinks confirm it's set, then to unset it, do the same sequence.
That plug shown turned into a test piece, I had new endmills and a new setup I hadn't used before so I skipped taking pictures of the process. I also got ahead of myself and took too much off the hex, the goal was 7/16"/11mm but I had to take it down to 10mm to cover the mistake. It will look cleaner with a larger hex/smaller gap to the outer ring and still fit a standard wall socket. This pic with a 10mm shows how much bigger it can be without getting too tight:
I can also put the hex-socket thing on the inside, around the OD of the spring, and copy the design of the stock stainless plug on the outside.
Tom, parasitic drain doesn't bother me. The lights that get used regularly go through a 25R every day, and the ones that don't get used don't eat enough power to make any difference. I have two lights sitting not locked out and in more than two months they're just now down below 4 volts (1 at 3.95v, 1 at 3.93v). At least some of that is the cells self-discharging which is still going to happen no matter what. If those two lights were at 4.05v after two months instead of 3.95, would it really be any different?
Yep, it’s not such a deal breaker to me either for the parasitic drain we are used to, just bugged me to waste away battery life for some unknown reason, and with our direct FET lights, dropping as little as 4.20v to 4.10v loses a fair amount of output. Now I/we know all the reasons pretty much, and I reduced the parasitic drain now by ~95% (from 0.314 Ma to 0.016 mA). The 220K and 47K resistor change over worked out well.
Of course the indicator LED’s I’ve been adding will eat that saved power up, but at least you can turn the indicator LED ON or OFF via a UI on the switch.
There's a bunch of boring tedious setup stuff before this - centering the part on the rotary table with the adjustable chuck plate, centering the rotary table under the spindle, setting the tool offset from center (0.055" dia, the table is offset half that (0.028") to the left so the left edge of the tool will be on center), etc.
Since the tripod mount thread is 1/4-20, I figured the hex should be the same as a 1/4-20 nut. Dimensions of 0.433" flat-to-flat, 0.492" point-to-point, & 0.219" thick. To set the depth, the tool is brought down to the top of the plug, and the sample nut placed under the depth stop. Then the total depth of cut will be the same as the thickness of the nut when the depth stop hits bottom.
The table is offset half the point-to-point diameter (0.246") to the left, and a groove is cut all the way around to full depth.
Next up is cutting the flats of the hex...
Sweet. What size end mill are you using? It looks bigger than I gather it is.
0.055" (1.4mm?) 2-flute, 1/8" shank.
That is small, less than a 1/16’’. I’d love to see the sweat on the brow operating that little bugger. Lots of RPM and small cuts?
It'll plunge cut fine, but side milling after it's to full depth I only take about 5 thou at a time. It might be fine with more but it's not like there's a boss or efficiency consultant standing behind me with a stopwatch on any of this...
Set the table to 0* for the first flat...
Next, 60*...
120*...
A little while later, 300*...
And back to 0*.
You sir have far more patience than I. Amazing effort so far. Looking forward to the next installment.
I was holding my breath going through the pictures in post #85….
I checked the drill press instructions and nowhere in it did they say 'DO NOT USE FLYCUTTERS IN THIS MACHINE', so I guess it's OK?
Wow! Again... Bringing the "nut light" to a whole new level! Brilliant work there, comfy.
The "nut light" was a cheapo multi-color zoomie with a nut glued on the side. I'm embarrassed to admit I own two of them.
Incredible. 
Very nice attention to detail! Looking at it first hand, how do you think the brass fares to aluminum or stainless?
Dumb struck. Amazing effort and what a sweet looking piece. May I ask how many hours went into this one item?