A camillus made barlow in sawcut delrin. I had it from 9 years old to 19, having it confiscated when arriving at boot camp.
I've had a thing for Sawcut delrin carbon steel barlows since then. Pretty much all barlows in fact, especially carbon steel ones. My "new" carry barlow is a remington green camillus made barlow, carbon steel of course, circa late 80's?
I was pretty poor then, starting out my state career and the "remington" knife was expensive to me compared to the "imperial Ireland" barlows in carbon steel that were available for under $5 just about everywhere. ( I got more than a few at Ace hardware, the most expensive knife in their display of imperials was $6.99 for a scout type knife)
I still have most of these knives, still sharp enough to dry shave with. I caught the Spyderco bug in 92 with the FRN Endura, but have began to come back to traditional slip joint folders starting a few years ago. My current favorites are GEC Northfield #23 liner lock 4.5" Spiral Buffalo horn, and Queen D2 line, Cocobolo ( when possible) 5.25" Folding hunter, or 4.5 " Mountain man.