If you use a SLA to power it you could put a Leviton toggle switch on it. 
After a bit of a hiatus, I am back in the game. Life was (and is still) hectic, but I'm devoting some time to this contest light now. I may crash and burn, but we'll see. I have endeavored to once again attempt making my own reflector. I've been down this road before with some success. But, it was not worth the effort for XM-L2 LED's. I've decided this light will have an MT-G2 and to my knowledge there are not really any great reflectors for that LED so it's worth a try making my own. I bought two gigantic reflectors that were made for SST's, but I don't have any stock large enough to make a head that will hold them and decided I wasn't going to spend the money to buy any.
So, I am using a method called "Spinning" to make the reflector. A flat sheet of previously polished aluminum will be bolted to a parabolic mandrel and a tool will be used to form the sheet metal to the mandrel as it spins in the lathe. So far, I have the parabolic mandrel made. It's 2.5" long and it's major diameter is 2.0" so it's depth is greater than it's width at the top. I'm hoping this will lend some throw to the previously unthowy MT-G2. We'll see. If I can't get the reflector to work out this project won't get off of the ground. I'm optimistic though.
Stainless Steel Mandrel being made:
Finished Mandrel
Nice!
Well, I hope you do work it out. The machine made category needs as many contestants as it can get. Heck, the hand made is looking kinda slim this year too. Good luck with it!
A daring idea to say the least.
The aluminum that I had didn't work out. It was too brittle.
I got some different, less brittle aluminum today. Going to try it out later tonight.
I succeeded in making a reflector(ish) object. It's a fairly large reflector, so the light will have to be largish as well.
After polishing
It has some imperfections, but I think it will do the trick. I can always make another one later.
Here's a video of me making the reflector. Some of the previous failures at the end...
I finished designing the head. Hopefully, I'll have pics and video tomorrow.
I don’t see the video link in either thread. 
It's embedded in the thread and it is there for me... Here is a link.
Nifty video. Thanks for posting it again. All I saw before was a blank page.
Hey! Are you cheating Scott? Looking at my O-L challenge build sheet?
(blank page) 
Yup. Most of my best ideas are someone else’s.
I'm aware of Scott doing this so I use my invisibility cloak over my blank sheet.
Very nice. Sort of like throwing a pot, but it takes a lot more pressure. Could you use a softer alloy?
I did some work on the head today.
Starting with this:
Machined the top for the bezel and the inside for the reflector.
Flipped it over and cut the pill pocket on the inside and cut the taper.
Threading the pocket for the pill is next. Last will be grooving.
I've already gone from harder alloys to 1100 Aluminum. It works much better.