I own a OCB 115 and can tell you that it has a well built box and that's the only good thing about it. The Tolex is very thin and rips and tears easily, the speaker is a Kappa 15A, nothing special, the box has no insulation from the factory. It would be a good cab at $350 new but for what they charge you can do a lot better for the money.
It doesn't have a horn.
If you want a nice 15 with a horn, try to find a Hartke Hydrive 15. You can find them used for what that OCB costs.
But it sounds like a nice used 410 would suit you better
It's 106 miles to Chicago. We've got a full tank of gas, half a pack of cigarettes, it's dark, and we're wearing sunglasses. Hit it.