Hi Grant: I don't know if you would call it "one off" but I came across them somewhat as a fluke. I was looking for these etc. under "reflectors" and all sorts of words and descriptions. As anyone who has shopped ebay, the key word is everything to finding something and low and behold I came across these under the word "prism". They are Czech chandelier crystals/decorations and as known, they make some of the finest crystal in the world. As soon as I saw them, I knew they were spot on. As said earlier, only 3 cm larger in diameter and that's close enough. I bought up their stock of eight and have a agreement with them to buy up all of them that they can lay their hands on. They have red ones of the same size, but as to an earlier broach of the subject, red ones were never used on CMP's. Nothing else even closely related to CMP's or anything military.
Hope this helps.....Robert