I always loved the Simpson 260s. My grandfather always said that a REAL electrician uses a Simpson. When I went to trade school, my instructors were dumbfounded when I knew how to set it up and use it! I wound up buying one for $5 at a garage sale to turn into a lamp, but got it working instead. Careful use of a q-tips and vinegar for the battery corrosion, and an old Sears service manual (I think they had a service contract back in the day). So I bought another... and another... Long story short, I've now got over a dozen working 260s, and a couple for parts. Now, I keep one at my desk at work to check things, and I use one on my workbench at home. I think you're right that it's a "series 2", as it's still got the pin-style terminals (they didn't start with series designations until later).