I have one exactly like that. I bought it at Fall Creek sutlery in the mid-1990s. Brass develops an antique patina pretty quickly. Even though I actually play mine fairly often, it looks like that. It came with a small, very conical french horn-like mouthpiece which I found difficult to play. Bought modern trumpet mouthpiece from a brass repair guy for $4 and solved the problem. I bet this bugle has a similar story.