You can see from those photos the sheet metal is stamped inward with a decent radius. On air cleaners with snorkels this area is stamped outward and is mostly square or a very tight radius.
I suppose a person could cut the flange off smooth and then figure out how to form the inward flange with the radius. Doing this would make the ovals larger but it probably wouldn't be noticeable to the untrained eye. Might be worth a shot to give it a try.
Post up if you figure out the process!
