Thanks for your 2 first suggestions but :

1) craftsuplies.co.uk doesn't carry "nutmeg" mechanisms :-(
2) The ones provided by Peter Child are even more expensive than the
French ones (http://www.hmdiffusion.com/Mecanisme-de-moulins-a-
muscade-5731p.htm)

What I was expecting were to find us suppliers (combined with the
conversion Dollar-Euro :-)

Thanks again for any tip :-)

JYS