It appears to me; from your photos, that it may be, that the ignition switch itself is OK, but the plug in connector & socket that connects the ignition switch to the car's wiring harness, is corroded & unserviceable. I may well be, that if you cut off the plug & socket, & substituted another generic plug & socket; or simply connected/soldered the wires together, without the plugs & sockets; then maybe the car will work perfectly. As You have the ignition switch out; You could test that the contacts inside the ignition switch connect OK, with a simple multimeter, or a battery & test light. Even if that is a temporary measure, to get you going again; it would then allow You time to search UK, French & German ebay sites, & see if anything comes up when looking for Neiman ignition barrels.
Even if You can't connect it up, without the plugs & sockets; then any good auto electrician, should be able to do that for you, & get You mobile.
Cheers Banjo