So when are we building the clams? Will you be happy as a clam? Will they be worth the clams?
Sorry, I got carried away. Thinking of pearls in oysters, being in a stew (with Stu), etc.
I'm back: seriously, we can start on a clam-shell enclosure and see what results. Are you thinking of routing a groove in the capping panels, or just attaching the pieces that fit inside the tube to the caps? We should be able to know something like that out in a weekend (finish may not be dry.) Might be good to experiment a little with duct size and stuffing on one before building the other.