Reading the forum and looking at the photo of the top cowling with the baffling witness marks there seems to be a couple of issues;
1. The ducts are not quite wide enough for the outboard baffles to seal against.
2. High pressure inlet air can flow under the duct and reduce the cooling. This is born out by before and after modification testing.
SOLUTION
1. Extend the ducts outboard to join the cowl.
2. Blank off the inboard end
After getting a good fit and clecoing I fitted the cowl and discovered the inoard end was too close to the flywheel so I trimmed the inboard ends with tin snips (worked a treat).
After the photo was taken I fitted the cowl to cure in position as per the instructions.
