I've never seen one of these in the wild before today. I thought I would share some pictures in case anyone has one, has more info on them, or comes across one.
I have no idea if they are desirable or worth anything more than a regular SKS. The mount is pinned and threaded properly, quality job. Unfortunately I will never use the setup. To be honest, after buying it I wish it was a plain old "regular" sks. The stock is cut for the mount, so just removing it is not an option. I could restock it, but I think I would cut out the replacement stock to allow the pins to fit. Not sure if those are welded in or not. This is from the distributor like this, not a home job.
This has non-matching serial numbers and appears to be from the ban era. It has a shaved bayo lug, and a clean front end with no sling loop. It was still filled with cosmoline and appeared to be unfired since import, but you can tell the parts themselves are used once I removed the cosmo. It was blued after the bayo lug was shaved, so I assume mid-late 90's import.