My recent Ebay purchase doesn't have a serial number. Hard to guess its vintage because it came with a non-original case. It's a straight soprano with a finish that's commonly called "nickel plated," although it sure looks like chrome to me. It has the other O.Borgani markings, including "esportasione mondiale" (worldwide exportation) and a star. No pearls. The register pads were a soft white rubber, since replaced by me. I'm guessing 20-30 years old, but I didn't know Borgani produced anything without a serial number. Where should the serial number be?
The seller said that it wouldn't play in tune, but my guess is that it wasn't tried with a soprano mouthpiece, as one was not included. When I tried it with an alto mp, I couldn't get anything within a note-and-a-half of what it should be. With a $5 no-name mouthpiece, it wasn't difficult to tune. Not perfect, but not bad. I've got a better mp on order and think I'll get a servicable student horn out of this.