Date of manufacture is determined from source material at http://homepages.ed.ac.uk/am/gdsl.html (archived HERE)

The Selmer-made Adolphe Sax horns are now in the Selmer gallery. You should give that a look, as some of the Selmer "Gen 1" horns are made from original AE Sax parts.
1st Gen
1st Gen
51 Rue Blanche
Double Octave Keys; No Rollers
2nd Gen
2nd Gen
84 Rue Myrha
3rd Gen
3rd Gen
"Curved" Wire Keyguards
"Y" Shaped Octave Mechanism
Buescher-like G#/C#/B/Bb Cluster
4th Gen
4th Gen
Redesigned, simpler octave key mechanism
Redesigned, more complex G#/C#/B/Bb cluster
s/n 14823 C melody tenor at MIMO

5th Gen
5th Gen
"Straight" Wire Keyguards
Bb Tenor Mouthpiece
Bb Tenor Mouthpiece
From jazz123john on ebay