It looks like one of the cheap stencils made during the 1950s - 1970s by Italian companies like Orsi, Grassi, Rampone, Santoni. It was not uncommon for parts to be exchanged with each other and the French company Malerne, so the provenance can be confusing. It might be a Malerne with body some funky Italian parts. This one is apparently a blank stencil that never got engraved by the merchandiser. Don't lose too much sleep over it.
This is a baritone sax manufactured by Couesnon. Its serial number dates the horn to 1974 or 1975. It is the latest Couesnon bari that I have ever seen, and it is also the only one that has ("IIb" model) rounded Eb/C keys. Thanks for posting!