Unsure which model Besson this is.  Based on the description it appears to be a Student 100XL model.  Serial # 404131 which indicates it was manufactured circa 1965.  It has stainless steel top spring valves, 2 forged water keys, 5" bell and a third valve slide ring.  All valves and slides move freely but a good cleaning is needed. It comes with one Blessing 7C mouthpiece, slide grease, valve oil and a cleaning brush.  It has numerous dents, scratches and tarnishes (see pictures).  The lip of the bell is bent, and the bell and back bend also have large dents (see pictures).  The retaining screw for the 3rd valve slide is missing.  Overall, the case is in good condition, but the case hardware is scratched and corroded.