The top Patent number is for the Haynes drawn tone hole process, the "A" is for Alto, the "L" is for low pitch i.e. A equals 440, and the M serial number puts the date of manufacture around 1926/1927 likely making this a New Wonder Series II horn (nick named the "Chu Berry" after Leon "Chu" or "Chew" Berry). Value is dependent on the condition and finish, which sight unseen is impossible to assess.