Faber Castell projection slide rule 310/88,89 case 1960 Germany

This special slide rule comes in the original and complete leather case with manuals and accessories and even the 57/88 normal slide rule. Made by Faber Castell from Germany. This model is the 310/88,89 for the both the Rietz models 57/88 and 57/89, a special slide rule made for use in the classroom as a teaching aid to be placed on a overhead projector or other beam / light source. It is a very high quality build with a slider and a moving cursor, all made out of separate pieces of Perspex. All parts are complete, it is working great and there are only minimal signs of use and age. The leather case is complete and in good condition as well, with the small Faber Castell logo dangling from the zipper. It measures ca 38 cm x 23 cm or ca. 15  x 9 inches. Do check the attached video on how to work your vintage man tool : slide rule operation instructions!