Saxophone with two octave keys

Last year I wrote a post about saxophone octave keys. I was surprised to discover, after playing saxophone for most of my life, that a saxophone has not one but two octave holes. Modern saxophones have one octave key, but two octave holes. Originally saxophones had a separate octave key for each octave hole; you had to use different octave keys for different notes.

I had not seen one of these old saxophones until Carlo Burkhardt sent me photos today of a Pierret Modele 5 Tenor Sax from around 1912.

Here's a closeup of the octave keys.

And here's a closeup of the bell where you can see the branding.