Late 80's to early 90s.
I talked to one of the princpals for Blue Sky later Arlington Ord. He told me when Arl. Ord. folded, He took a barn full of stuff to his farm. He told me he had a box full of flip rear sights somewhere in the barn. They took them off because at the time they did not believe carbines would sell with the "Old Parts" on them. He never found the box for me but I did get some stocks from him with chicken sh1T on them. I should have paided him a visit.
I also got from him receivers with the dovetail busted off, one side or the other, where they were removing flip sights. The dove tail will break.