Cusser
+1y
Just draw one onto metal using your EGR gasket as a template. Make a mounting ear for a Weber return spring while you're making it (I forgot to do that with mine. I used a EGR gasket with Permatex Aviation to seal mine.
I plugged the four exhaust holes on on the exhaust manifold with solid lug nuts from O'Reillys ($6/set), believe these were 14mm x 1.5 thread. If you are talking about plugging the three rubber tubes near the air cleaner, I used rubber stoppers in those.
When I removed the metal tubes, I made a block off plate for that similarly, down under the first cat.