What Knarfeng said was correct.
Hard to know a whole lot more about the old Primbles, they used quite a few different manufacturers to make their knives.
Some of the ones used are:
George Wostenholm Cutlery
Roberson
H. Boker
Schrade
Schrade-Walden
Camillus
Case...(only "Baby Doctor" patterns very early on)
Queen
Currently Blue Grass Cutlery owns the name and has contracted new John Primbles from overseas.
I own seven of the old ones and the blades are all carbon steel or alloy carbon steel, not stainless steel - in other words they will patina.
and a little more Primble history from Bernard Levine:
"John Primble" was originally the premium private brand of the Louisville, Kentucky, wholesale hardware distributor Belknap Hardware Co.
Belknap was founded about 1840. In about 1890 Belknap first began to use the brand JOHN PRIMBLE, INDIA STEEL WORKS on its premium quality cutlery. This brand continued in use until about 1940.
After World War II, in 1947, Belknap began to use the brand JOHN PRIMBLE on its premium grade cutlery. PRIMBLE knives were made for Belknap by such firms as Boker, Camillus, Utica, and Schrade-Walden. This PRIMBLE brand continued in use until Belknap went out of business in 1985.
When Belknap closed, its Primble and Blue Grass brands were purchased by Roy Scott, then of Ohio, who founded Blue Grass Cutlery Company. He also acquired the rights to sell WINCHESTER brand knives.
Since that time, Blue Grass has made a specialty of selling traditional pattern pocketknives made with traditional materials to a high standard of quality. These knives have proven to be very popular with collectors. They offer an opportunity to own fine traditional pocketknives at a fraction of the cost of antiques.