The late Marcel Jurca was one of France's most prolific homebuilt aircraft designers, responsible for a series of mostly high-performance and often aerobatic designs generally of wooden construction. He also designed a series of replica warbirds from a 2/3 scale P51 Mustang up to full-scale Bf109 and Spitfire. Plans for many of these designs are still available from http://www.marcel-jurca.com. Here are four somewhat unusual designs that never became available to homebuilders. The source of this info and these images is the web site above--I have paper and electronic files of other French homebuilts to share, but I thought I'd get this thread started.
MJ-14 Fourtouna: The prototype of this racy, single-place, retractable-gear, single-engine (100-160 horsepower) was started in the 1970s but is still incomplete. Plans were complete but never made available in the absence of a flying prototype to work out the kinks.
MJ-22 Bi-Tempête: The MJ-22 is a twin-fuselage (hey, Tophe!), twin-engine development of Jurca's iconic aerobatic MJ-02 Tempête, his most popular single-place design with well over 50 completed and flown. The MJ-22 was an initial design study only, plans were never completed and none were built, the photo below is an artist's impression only. Note the
signature MJ-02 rudder profile reputedly inspired by the Douglas AD-1 Skyraider.
MJ-23 Orage: This high-performance racer and aerobat was intended for a 200-300 horsepower engine with the option of flaps and retractable gear. The low-powered version reused the wing from the MJ-02, the high-powered version the wings from the two-seat MJ-55 Biso. Plans were never completed, so none built.
MJ-6 Crivats twin: Here's something you don't see every day: a tandem two-seat light twin, 2 x 115-150 horsepower engines, retractable tricycle gear. Plans were completed but the prototype was not so plans were never made available to amateur builders.