WWII Trumpet

Have a trumpet from my father in law that he used in the military in the 1940's.  It has inscriptions at the top and some of it says "antoine courtois brevete"  also has Paris and New York in the inscription.  I know nothing of this musical instrument and would like to sell it since it is doing nothing gathering dust but would like to have an idea of what to ask for it.  It comes in a wooden case.