I still have, and can actually find, the first slide rule I ever had. A plastic Pickett model 120, and I have both the sleeve and the instruction booklet for it as well. Got it as a gift I think when I was a sophomore in high school, probably 1962. I also still have a Pickett N3-ES that I used during college and into my first job upon graduation - somewhere along the way it has managed to lose one of the screws holding the piece with the K, A and extended SQRT scales in place. There’s also a 6" Pickett somewhere in the house. Sadly, I’m more than a bit rusty as far as using them is concerned. Needing +3 reading glasses to use them at all isn’t helping.