Advertising for the model 9 Sangamo Special movements showing a 23 jewel crosshatch pattern movement with screw down balance jewel setting, large escape jewel setting, true bridge, and serial number 2575893. Interesting to note the sales prices for the 23 jewel ($45), the 21 jewel ($38), and the 19 jewel ($33.75) and that there is no mention made of the hunting case model 8 movements here.
The booklet this ad is from has a nice image of the Illinois Watch Co. observatory on the cover.