Here's a signed private line Key-On-Board made by Jerome Redding in Boston in the 1870's. The instrument comprises a telegraph key and sounder mounted on a large, heavy, decorative cast iron base. In the ad pictured above, published in 1877, the KOB is described as the company's "No. 1 Private Line Instrument."
Condition is as pictured, with wear to the black enameled finish, but a fair amount of the original decorations still visible. It's a good candidate for cosmetic restoration if you've got the skills to undertake one. Or you can leave it as it is -- it's an uncommon apparatus in any condition. There's no damage to the cast iron, and all of the small hardware appears to be in good shape.
The lever needs a new spring.
Please review the photographs and consider them an integral part of the description.