Paul,
I know from experience that Depanoto has a vast collection of used parts they don’t advertise. However, you have to visit and literally bang on the counter before they will admit they have anything – and then bang twice as hard again to persuade them to look for it.
A less stressful route might be to join the French Rosalie Owners Club …..
https://share.google/GC7s4d6ukvFwro5XW
If they are anything like the French 5HP Amicale, they will be most helpful.
Good luck.
B….