Help ID these STANAG mounts (FAL and others?)

Hello everyone,
as longtime reader I hope here is the best place to find the knowledge I need and what some days of google search could not provide.

I recently got my hands on a cheap bunch of STANAG mounts that all appear to be from the same country or military origin because of the method of mounting, manufacturing process (all milled items) and dimensions of dovetails and so on, that are all very much alike. One is clearly a metric FN FAL dustcover mount. There is a similar one with the corresponding STANAG dovetail currently on eBay for a very high price. The rest ist totally unknown to me, because its missing any kind of markings except some matching serial numbers here and there.

So let me start:

1.
https://www.milsurps.com/images/impo...584dfsct-1.jpg

This is the FAL mount. There is one on eBay with the coresponding STANAG dovetail. Here the link to the picture for refference: !click me!
Questions are now: To what metric FAL does it belong. What was mounted on it. A STANAG scope or night vision scope? What countries or militarys used them on what FAL variant. What was the scope that was mounted on these mounts?

2.
https://www.milsurps.com/images/impo...585sts0p-1.jpg
https://www.milsurps.com/images/impo...586hnsd9-1.jpg https://www.milsurps.com/images/impo...5885bsv8-1.jpg

This is a mount thats fittet on the right sight of ... well i don't know of what but its fitted with two screws. Below the dovetailed slide with the STANAG mount are the two holes for mounting.

3.
https://www.milsurps.com/images/impo...589z8s8d-1.jpg
https://www.milsurps.com/images/impo...590ops80-1.jpg https://www.milsurps.com/images/impo...591cmsgo-1.jpg

Next one is of similar construction design like the 2nd one but is somewhat different. The dovetail slide is wider and not as long as the first one. I also suspect this would be mounted on the right side of whatever it was mounted to, because the screw pointing to the user allows the slide to be slide back for quick unmounting. A bit like with PVS-2/IWS mounts.

4.
https://www.milsurps.com/images/impo...592xqs7z-1.jpg
https://www.milsurps.com/images/impo...593c8se6-1.jpg

Last piece is another STANAG dovetail but it does not fit onto any of the previous mounts. The dovetail dimensions are the same like the ones from the FAL mount and the 3rd mount but all of them are not interchangeable because the guide post in the middle is always placed somewhere different or the fixing mechanism would not correspond. Also this one seemed to be design to fit onto the left side of whatever it belongs too, because the guidepost cut is somewhat mirrored to the dovetail from the 3rd mount, while keeping the exact same overall dovetail dimensions.

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So all these items are a huge mystery to me. I tried to find some informations or pictures around mainly with night vision based keywords, but could not find anything helpful. The items are clearly very low profile mounts and require some substantial rise for any tubular scope or night vision to be directly mounted to them. They are also missing any kind of elevation or windage adjustments so whatever is mounted on them must have these options build in.

Just out of curiosity i tried to see how these mounts would fit onto a PVS-2.
https://www.milsurps.com/images/impo...594ghskh-1.jpg
On this picture you can clearly see that the shape or the mount is way to narrow for the big gen1 tube device to fit. Because many gen1 night vision scope i know of, have similar STANAG sockets, im very curious what these mounts where made for. Are they even intended for optics or rifles/machine guns? The dovetail "quick change" mechanics would suggest it, also the pretty similar constructed FAL mount.

So is there anyone out there with some knowledge about these mounting systems or even has some pictures where they are applied?

Sorry for my english, im not a native speaker :surrender:.

Thanks alot,
-Sebastian