I went to a local shop that has a reputation for working on older bikes. I got a new crank axle and cotters for my old Motobecane for about $15.
Steve
EDIT: Here's one... can't say if it's the right size:
https://www.niagaracycle.com/categor...-55-x-51-x-152
Last edited by sweeks; 12-17-17 at 03:48 PM.