1. Fitted the aft-right baffle piece, then installed the oil cooler and plenum, to get an idea of how the oil cooler butterfly valve will need to be positioned.
2. Assembled the shutter valve arm and plate. Held the assembly in position on the front side of the valve cutout, and found that the valve makes contact with the plenum as it opens -- it cannot be opened more than about halfway.
3, Marked the point of contact, removed the plenum and cooler, and cut an opening in the plenum. Did this three times in order to creep up on the proper hole size and shape. Reinstalled everything to verify that the valve plate will clear the edges of the opening.
5. Prepped the plenum by scuffing and cleaning it.
5. Cut three rectangles of medium-weight fiberglass cloth. Mixed some West Systems epoxy resin and applied the three layers to the plenum, pushing out a bump in the cloth to give the valve the clearance it needs. I'll let this dry, and tomorrow we'll see how it works.