I made a round steel plate from 20 or 22 ga steel and sandwiched it under one of the clamps on the gaiters. It took a little shaping with a ball peen hammer on a wood block about 15-20 minutes. My original intent was to make a cover plate for the intake port too but it was easier just to put the plate in-line and leave the mechanism in place but non-functional. You really don't need more than that as it blocks the flow.
