Sabre was a brand name used by Cole National of Cleveland, Ohio on a low-priced line of knives. Cole National used to own the KA-BAR trademark; that was used on their "best" line of knives. Monarch was their mid-grade brand, and Sabre was their low-end brand.
At various times, they had the Sabre brand knives made in Solingen, Germany (your knife is one of these)...and also in Japan, and in the USA by Colonial knife company. The Japan versions are by far the most plentiful and most well known.
As to when your knife was made, a guess would be mid to late 1960's. The Solingen made Sabre knives are relatively scarce.