Holy bucket of merde, Batman - that is it!! I was wondering why it had an L. I mean, I knew that the French were weird about their bike stuff (like thumbing their noses at threading standards), but they don’t just randomly stamp stuff in their gear.

I checked the threads with a right pedal - it went in half way by hand before it got stiff. Then I checked a left pedal and it did the same thing! The threads are crossed, I can see it looking close up. But the left arm is a legit left arm.

And of course the lack of an inner shelf is because this was for the single ring of a timing chain only. Why waste material with that extra shelf?

However, this all makes me a little nervous - I don’t know if I’d want to use that as a single speed crank now that I know that it has be re-tapped for a right pedal.

BF members for the win!
Nice job, Encyclopedia Brown!