I'd have to guess, the "plumber".

So you have one of the timers, it's beautiful and in pristine condition too. The ones that we used had red labeling or screen printing, but theylooked exactly as the one from your "red box". These were actually used to cut the fuel to the engine as I recall, correct? The spring actuated arm pinched off the surgical tubing used in the fuel line. This awakens some great modeling memories/moments with my Dad, I wish I could share that and this thread with him; but alas, a major stroke took care of that four years ago. But I do show him the pictures and that brings a smile and a gleam to his face; and it has led me to be involved in modeling or aviation for most of my life so far! Thanks Cees.
Mark