IMO, the nite vision or jambo are not alike at all, missing the screws on the lenses, plus the arms are totally different. Just the frame is similar..
But totally agree on the fact they become super hard to find.
Finding the cheap copies, especially in black/mirrored color, is however pretty easy.
You were taking about the fact they might be custom, but they are not. As I said to Naycooke, I saw few days ago a (pretty stupid) soap which used to be broadcasted when I was a kid (around 1996) and one of the protagonists had the exact same glasses (with yellow lenses too), in several episodes.