I like the cold beer best, then let all good ideas slip back into oblivion.
I just worked out a Yak with a customer. Some very simple disk attached to the firewall, and some sticky window foam in the cowl did the trick. A cardboard template was cut out in 5 minutes, and it sported both the baffle, and bent back tabs acted as the air guide jacket alongside the fins. Had we made it out of coroplast, we would have needed nothing else.