Well you know if you live anywhere in France (excluding colonies) then you can drive to anywhere in the UK within two or three days, so castings should be no problem at all, provided you want a British prototype of course. Try shipping them across the world to NZ or Australia, you are likely to pay as much for shipping as for the bits. Not to mention getting taxed for the shipping costs themselves.
There are, or at least were when I was over there ten years back, suppliers on the Continent, mainly Swiss or German, who could supply suitable screws and nuts and other bits in metric sizes for ME purposes. I picked up all sorts of price lists at the Sinsheim show. I realise that for a French speaker, Sinsheim itself and mostly the brochures would be in the wrong language, however when I was there I had about zero German language and I got on fine with folks by taking along a Stuart 10V as a “conversation starter”.
France has a wealth of interesting engineering history, and it would be great to see some French projects make their way into print….
regards
John