This information from Aaron:
Amolette was a player & teacher from the Paris Conservatory who moved to Boston and was highly respected in the symphony world. He sold a line of high end clarinets under his name. There were symphony players who preferred his to Buffet. I saw a Bb of his years ago in good condition but it was WAY out of my price range. 

Thanks to Denise who corrected the spelling to Amelotte.

This just looks like a Couesnon-made stencil to me.