Here is a table of serial numbers of Saxes made by Beaugnier
The first list is branded 'Noblet', the second list is branded 'Beaugnier'.
The third list is branded 'LeBlanc', the fourth list is all other stencils.
Some of the serial numbers are clickable links that take you to pictures of that horn.
Vito-branded horns have a seperate serial number list.
I update and expand this list as I have time.
If you have a sax that fits in this list, I'd love to get the serial number and pictures and add it in.

Model name "Face" indicates there is a face on bell brace and neck.

Check out this comparison of two Noblet alto saxes.

"RH Bellkeys" indicates Right-hand bellkeys (from players perspective).
The numbers sometimes following "RH Bellkeys" indicate which keys, numbering keys from neck to bell, with High F being #1 and low Bb being #22.
I've got a question mark after one serial number because it was so hard to read.
I've got 2 question marks after a year because I was dubious of the owner's assessment.
I just read that the LeBlanc Rationale was nade only from 1950 to 1953. The instruments sure seem 50's to me for some reason.