Yeah
Just write "besson and co serial numbers" in a search and out will pop many sites that have info on serial numbers.
Or just go to
www.musictrader.com/serialnos.html
I had only a quick look at 2 and narrowed it down to these dates, if you look at more it may give you the actual year.
BTW a lot of that was happening at the time, big companies making horns for shops in other countries and the shops or people having their names put on.
The same models as yours by besson were also sold to a shop in Australia and had that guys name on! forget what the name was but its all there in that search info.
Good Luck
Leigh