thanks, the pictures are atrociously small to see any of the many important details essential to identify this horn.
Pre-war Selmer? Yes but quite a bit older than the more desirable models. So, if indeed this is a Henri Selmer baritone, due to its left hand bell keys, the upper octave key on the neck and the brace this “ could be “ a ’20 Selmer. Maybe one of those Adolphe Sax models?
The G# is strange, for a saxophone of that era, they were mostly round buttons which due to their awkwardness were often replaced on several brands of horns, on the other hand this could be original and meaning that this saxophone is not what it appears to be.
The price is whatever it is, adequate, but I would certainly ask for larger and more detailed pictures and a serial number before making any move.