Need help with Makers Mark ID on brooch! Thanks!!

[rainbowtree117]

Victorian/Edwardian repro? M in square makers mark?

[okon2]

 I michelson & sons , that is what I found , THis is the mark used after 1931 ,  If im right

[rainbowtree117]

Thank you so much for your time & input! I agree that you may be correct. with your findings.