I think Steve(MRsDNF) buys o-ring material and cuts it to length and glues it himself.
Go to HD or Lowe's and find where the sheet metal and rod is. You can use a piece of steel rod thin enough to form, but stiff enough to not use shape. Then, if you have a dremel or something you can use a ball end cutter with, you can cut a groove and make the metal rod so it just snaps in place and locks the lens in. It would be a good way to hold the lens in and still not cover up any of the lens, so to speak.
On a few rare occassions I’ve had a large light that the glass rattled once modded. I use the same Turnigy wire I’ve got an abundance of (pick the right ga for the job) and make a ring of this. Fitting it into the bezel for length, I pull back the Silicone sheath and solder the ends, then push the sheath back in place for a continuous silicone “o-ring”. 
Should pretty much be water proof right up to that split in the sheath. Rain and such I’d say yeah, not gonna take being under water very long but it’ll slow it down. 
Check out the OP. Big update today
looking forward to the beam shots on this!
Is that a joiner for the s bend of the back of a toilet? Nice machine work with the sander.
Whatcha talking about?
Willis (me) knows what he's talking about but as usual no one else does.
I'm looking forward to the next installment.
Trying to say your mind is always in the toilet?
His mind is always down under
Nice work and problem solving on the lens barrel.
Neat idea. I’m really liking this build.
You might be able to braze a bit of thread from another tip onto the plastiweld tip. Or buy a new one. I like the way you used the shape of the coupler end to make some pieces.
Thanks. That bezel isn’t going anywhere. I just have to fill in some gaps. I may go get another from harbor freight. They aren’t expensive
I plan to mount the lens tonight if I have time. I’m currently 4 hours away moving my daughter into the Mississippi School of Math and Science for her Junior and Senior year of high school. I’m extremely proud of her, but it’s sad to have her out of the house 2 years early. I won’t get home until dark, so it should be cool enough to get some work done if I’m not too tired.
Ugh, I didn’t get home until 10:30pm last night. I was exhausted and fell asleep on the couch soon after getting home. It was a looooooong day yesterday. I woke up this morning sore from moving stuff up stairs to my daughter’s dorm room on the 3rd floor. Anyway, I made some gaskets for the Lens retaining rings. I also posted some info about a new idea
A lot of work and thinking has been done so far... Thinking about project and combine that with family responsibility is not easy. You literally have to beat yourself in this project.But one day you'll have something unique to pass on your children/grandchildren. And if zombie apocalypse really happens maybe it will help to survive(along with few .357 mag, or 10 ga shotgun, or some very nice AR just in case ;) )
See the OP. The lens is officially installed!!! 
Now I’m off to get some sleep.
Nice work on the lens mounting. I'm starting to understand this piece of the light now.
i’m picturing a gun on a Naval Destroyer ship for some reason here. 