I'd be happy to help. The serial number would indicate a 1928 Conn New Wonder. Can you post a couple photos of the sax here? That would be most helpful.
Looks nice! Does your G# keytouch have a cross-hatch pattern? Couldn't really tell from the photo. If it does, that's the telltale sign that it is a New Wonder II, or "Chu Berry" horn. Am I mistaken, or does it have body post type stops for the D and Eb palm keys?
Correct! The cross-hatch G# was adopted at about 140xxx, so a 178xxx should definitely have this and would certainly be what we refer to as New Wonder series II or "Chu Berry".