According to the data seen here, ser# 91348 puts it in 1966 which is confusing considering the info posted by stonecreek and Old Hippie. Lots of head scratching with these old Sakos. Makes it interesting for sure. http://thehunterslife.com/forums/showthread.php?t=14777 I did remove the ladder from the rear sight and mounted a VX-1 3-9 from the cabinet. I've had these high Leupold rings sitting here for years and doubted I'd ever use them but there they are. A bit higher than I like to mount them but it leaves the rear sight base unmodified and I can easily reinstall the ladder. I may have to search out a Burris Mini as posted by icebear. I do have the Sako rings that would work. I shot it with some 50 gr Ballistic Tips and IMR4198. Groups were about 1-1/4" for 5 shots.