1. The rule, made by Hemmi in Japan, is a close copy of a Faber Castell electrical slide rule. The cursor even fits my Faber Castell 378 electrical rule (which coincidentally does not have its cursor.)

2. Not only has Hemmi copied the layout of the rule it has also copied the digit registering cursor. The basic idea of the cursor was that the position of the slide, and/or the relative position of the answer and the cursor, could indicate indicate if the number of significant digits had increased or reduced - the user could then record this on the cursor. On the Faber rule this type of cursor lasted until the first World War (1914).

3. This rule does have the symbols of the form <+|-> and the mnemonics "Qout +1" (for quotient plus 1 digit) and "Prod -1" (for product minus 1 digit) to complement the cursor. These are not on the Faber Castell 378.