I don't know if I qualify as an "older guy" (I'm 53), but when I was a kid back in the 70's I carried a Calillus TL-29, with that big screw driver, and one of those flat, four-pointed Craftsman keychain screw drivers.
The TL-29 was my first "big" knife. My father was a civilian worker at the North Island Navy base here in San Diego, and apparently TL-29's were commonplace. He would often bring one home after using it at work all day, forget to take it back, grab another at work, and then eventually bring that one home. I collected several throughout my childhood. Eventually I started selling them to kids at school. I still have one of them that I use in my garage when I need a sharp, curved edge that I don't care about ruining (below).