Might want to ask the manager at Lowes where they got it. It's very possible they just got a piece of metal and used various taps that they probably stock to make the holes.
My dad has a tap and die set, so I tend to just use those to see what fits, but it's not necessarily the most efficient method 🙂 That and I live a couple states away. Maybe I should get my own, now that I think about it.