Definitely not OEM but not much on my bike is original anymore...
The tricky part of the bracket is having the equipment to drill a hole big enough for the ignition switch hole. I have an entire high school metal shop at my disposal so I have large diameter taper shank drill bits and heavy duty drill presses to fit them.
Anybody could use a die grinder and hog out that hole if they didn't have the equipment to drill a hole that big.