OK this is a small matter but I use my small metal ruler many times every day . .
Would you be able to source a metal ruler with cm / mm measurements on both edges of one side of the ruler both measured from the same end? I used to have one and only realised how wonderful it was when it went awol.
I never use inches for this kind of length (and have a tape measure for longer lengths eg to measure chains which is about my only need for inches).
Also whilst its useful to have conversion tables for in / mm but I really don't need it on a ruler. I need measurements.