I think scribing T/S on mainsprings and great wheels is more use than harm. I never seem to memorize the direction of the wheels and sometimes pictures don't work out. Of course, this is not acceptable on expensive clocks but what harm can it do to a crude T/S clock? It is also such a minute detail that only persnickety people will pay attention to. I think it would be useful to future clock repairers as well.
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