Sabre flooded the low price market in the '60's/'70's with a wide variety of fair using knives, salesman samplers, and business incentive pieces. Displays weren't uncommon, just like Ruko (?) at the ag stores locally.
For quality they aren't bad - the price was low, but the workmanship was pretty good, especially compared to the early Chinese/Pakistani imports these days. I've compared them to some of my folders from the "better" US makes of recent manufacture, and they come off equal.
Knife steels are more of an unknown, 420 being highly likely, but they may have used some 440C, which is not bad. With a proper sharpening, you could do worse carrying a newer knife.
If someone was looking for an inexpensive brand to collect, Sabre would be a good choice because of the unusual number of different styles over the years - especially in "office" penknives. And of course, Japanese construction is much more highly regarded in these days than it was.
If the Gerber Mk II's weren't ground by a Sabre supplier, they were probably ground across the street.