OK, See photos which show the newly installed throttle spring and hold down for the hand crank. The accelerator footrest beat me, I couldn't access the reverse side of the body to fit the retaining nut - drat! I'll have to work on that one.
However, with the new spring installed I was able to properly adjust the carb to get the idling speed just right. Now the engine starts better both hot and cold and idles lovely, marvellous! I also found the number of the body tub, picture below. This is an early Hotchkiss manufactured body, very close in design to the US made ones. The hand crank hold down is a good example - the stud was in the right place and has the right non-metric thread to take the wing nut! Same story with the horn and oil can brackets, right place, right threads - Vive la France!