The spec sheet or photos (or both) would help.
Image intensifiers are not digital technology, but more like an offshoot of old CRT TV tech. It is a very low-yield manufacturing process, and a huge number are fully scrapped. Setting aside the complexity of how you get high resolution and brightness, there is no such thing as a perfect tube; all have flaws of some sort or another. You can find "apparently" flawless tubes (the flaws are not visible) but they are there. And they are VERY EXPENSIVE as they are in demand.
A very nice moncular is in the mid-$3000 range. For a price comparison, broadcast quality image intensifiers (the clip between the camera and lens assembly...
I have one) have apparently flawless tubes, not especially complex attachments at each end, are not waterproof or anything and cost around $8,000.
Aviation tubes are the highest commonly-available, milspec quality things because aviation demands everything be flawless...

No, because they fly around in empty skies, oceans, tractless desert and flaws can look like targets, other aircraft, etc. so confuse you. In ground mode, there's crap everywhere so it doesn;t matter. Stop looking at the tube, look at the image. Walk around and see things. You'll never notice the flaws in practice.