The serial Number puts it's date of manufacture between 1923 and 1924, which would likely make it a New Wonder Series I. There should be a letter both above the serial number and below, which will tell: 1. you what type of horn you have i.e. Alto/Tenor etc. An "A" will appear above the serial number for Alto, a "T" for Tenor and so on. 3. An "L" or "H" should appear below the number, for (L)ow pitch, or (H)ighpitch. The former is what you want, which means that it is pitched to A=440. The second, or High pitched instruments are out of tune with modern instruments, and is next to useless. Your horn is Silver plate over brass, not SOLID sterling Silver BTW. If you provide photos, I can positively ID your horn for you. Cheers.