Pre-WW2 Fabrique Nationale in France somewhere.
Possibly a Fabrique Nationale 1925
By the end of World War I, after having to manufacture motorcycles for their occupiers, FN had few parts left, and some suppliers had gone. From 1921 the letter "T" was added to model names. The Type 700T Four had a three-speed gearbox. In 1922 the Type 285TT single had an improved cylinder head. Also the first racer, the Type VII was built.[2]
From 1924, all models had the less expensive chain drive. Most of these were sv and ohv 348 cc and 498 cc singles. The FN M70 "Sahara" 348cc side valve was the most produced FN motorcycle of the interwar period. It was famous for as the name says crossing the Sahara in the 1920s. The FN M90 was as 498cc side valve which was produced in the 1930s. There were also 596 cc ohv machines. The FN M86 is very nice example of a 498cc ohv built in the 1930s. From 1924 FN single-cylinder engines changed from semi unit construction (as seen in the last semi-unit single, the 1922 FN 285TT, in its last year of sale in 1924,) to unit construction engines (as seen in the new-for-1924 M.60). A new chain driven M.50 Four was released with a new Amac carburettor and front brakes.[3] In 1931 a Villiers 198 cc two-stroke FN model appeared. In 1938, the M.12 992 cc air-cooled sv flat twin was built for military use, and the all alloy M.11 was released in 350 cc ohv, 500 cc sv and 600 cc sv models. Then World War II intervened. An M.12 Tri-car was developed and produced for military use.[3]
https://en.wikipedia.org/wiki/FN_(motorcycle)