Many thanks to you for those suggestions. The serial number is almost totally hidden towards the bottom of the body tube under the rods for the low Eb/C, just as suggested by nigeld and by Graysax.
It turns out to read 24,9xx and the chart here: https://www.saxophone.org/museum/serialNumbers tells me that means 1976/77 well into the S-1 model run. I have no idea why S-1 is not marked on the instrument.
Rhys
It turns out to read 24,9xx and the chart here: https://www.saxophone.org/museum/serialNumbers tells me that means 1976/77 well into the S-1 model run. I have no idea why S-1 is not marked on the instrument.
Rhys