OK Here is whay I did for my 1650 gas.

I called Maibach, 1-800-808-9934, and they sent me down a flat piece of metal with many small holes.
I was concerned that the engine would not get enoug air under heavy work so I cut the middle out and used screen porch screen, 2 layers, and fishing line to make my new screen.

Looks great and works greater and is much less expensive than AGCO!

Good Luck

Don