Buescher True Tone.  Considered Professional level.  Blued steel springs.  Blued steel insertion plates in flat spring channels.   No “made in france” stamp anywhere though – not sure if they were manufactured directly by Buescher or possible a stencil from Conn or anyone else.  Buescher True Tone Clarinet

Buescher 400 clarinets were stencils from Selmer USA.  Similar to the Selmer Signet 100 or 200.