1. A clear basic Reitz rule.
2. The cursor has hair lines for HP/kW conversions for C/D and A/B scales.
3. It is easy to see why the Reitz layout became popular. The R, Reciprocal scale (CI   on most rules), minimised movements relative to a Mannheim rule,  the S ST and T scales on the back of the slide gave a full range of trig values and the log scale could be used, with support from pen and paper, for expressions involving exponents.
4. I also show some images of the a later version of the same rule.

Front view

Detail - front left

Detail - front right

Front view - later rule

Detail - front left

Detail - front right