I have just acquired this French side cap. It’s wool and was in rag order when I first got it but have cleaned it up gently. No holes and is stamped inside (see pics). It’s army but I’m unsure on Corps or age. I have been advised French Medical Corps for a pte soldier, is this correct?

Also the stamps with any likely age numbers on are slightly worn. I can make out: 19 11 56 in the lozenge between the 2 diamond stamps. Also in the middle rectangle stamp there is: something something 36?

Can anyone enlighten me as to its age please?

Many thanks

Al