There should be at least one more digit in the serial number. Does the horn have any engraving? What is the engraving design? The serial number you have given indicates that your horn was made in 1905. This would be a Conn Wonder model. I really doubt that it's that old. If it is indeed that old, it will have a union label stamp on the back of the body near the thumbrest. This horn would also have a double octave key, which would make it unsuitable for a young student.