Nice piece, i should have filed a patent 6 years ago when I came up with the same idea and made my own to fit a 4150 on my M1 4500 intake. The pic shows the combo plate and a 4 hole spacer.

Made mine for the price of scrap aluminum 1/2" plate and my Dad's time on the mill. He has since retired and so did my freebies with the mill until I get my own unit.