It's a bit of a sketchy lead, but it seems that some variants of B. E. Meyers' 'Dark Invader' scope, like Jesse3959's, were assigned National Stock Numbers — which means they were entered into the federal procurement system.
Here's an example:
https://www.wbparts.com/rfq/5855-01-447-9151.html
Scroll down to Management and there is a "Navy" tab there, with various bits of inventory management metadata. This doesn't exist for other B. E. Meyers NV scopes, so it looks like this particular one was purchased by the Navy at some point in the late 90s. There could still be some hanging around.
There are some commercially available databases where you can search for procurement history by NSN, but nothing available to the public. And also there's no way to verify if this particular model would have had the adjustable iris.
Mine was previously owned by Missouri State Troupers - still had the inventory control sticker on it, or at least half the sticker. I got it on ebay about 10 years ago, and the auction said something like "Been sitting in storage for 10 years, does not work. For parts or repair. $500."
So I took a gamble on it. It came in a pelican style case with the hardware to mount it on a rifle scope.
It's definitely a model that was marketed to military and police type customers. It's eye-piece lens is specifically designed to be very large diameter which means it can work in front of a camera or scope or whatnot, even a camera that has a large input lens.
It's also designed to have a magnification of about 1x -- so however big something looks through the NVD is the same as without the NVD, so it doesn't change angle measuring through the scope or size/distance estimations.
The really sad part is there were two for sale, each $500, identical, it said they didn't work.
I've been kicking myself for a decade for not getting them both.
I just got the one, tried it, it didn't work, so I tore it all apart, tested the imager tube on a benchtop power supply, and it worked.
Then I looked at the manual *which was included* and on the first page it read WARNING: DEVICE WILL NOT TURN ON EXCEPT IN THE DARK.
so I tried it in the dark and it works. It's a safety feature to protect the image intensifier tube.
And the seller hadn't read the manual either, which is why they listed them as not working... I could have had two perfectly good $2000 gen3 NVD for $500 each if I'd just taken a little more chance. But that's life LOL.