I just purchased a 3 bottom plow on a Big Iron auction. Its a Dearborn 3 bottom plow for $23. It has a U-channel bolted to the top of it - can anyone tell me if the u-channel was factory installed or if it was a farmer repair. The link to the auction pictures is http://www.bigiron.com/Lots/Dearborn10-13BottomPlow-2 Thank you