Sterling Plastics 589 Senior Duplex Slide Rule - w Instructions and Case - 1960s For Sale

Sterling Plastics 589 Senior Duplex Slide Rule - w Instructions and Vinyl Case - 1960s Vintage This is a duplex slide rule from Sterling Plastics. I believe this is from the late 1960s, and according to a big slide rule museum site, this is the older model 589, with scales of A [B, CI, C] D, K on the front, and trig scales of S, L, T on the backside. As a disclaimer, I am totally clueless on these things, and am merely reporting what was shown on the previously mentioned SR museum site. That said, it comes as shown, in over all very nice condition. It has its vinyl storage sleeve, and a rather beat up, but still quite usable instruction sheet. See pictures for details.