1. The word "Japan" is stamped faintly on the back. It can be just be seen on the image below. This is a common practice of rules made in one country being sold in another under a "local" brand name.
3. It is unusual in having cursor hair lines for conversion to kilowatt for both British/US (746) and European (736)  horsepower. The first was based on the energy to lift a 550 pound weight through 1 foot in one second ; the second was based on the energy to lift 75 kilograms through 1 metre in 1 second. In the image below one of the short lines is aligned with the 10 mark on the A scale and the principal line is aligned with the 736. If the other short line is aligned with the 10 then the principal line is aligned with 746.