Well Keith, it was just cracked at the last service, appears the grease and tape method didn't work for meπ
Miklos, that's a good tip. I drew a pencil line around the tunnel before removal, this helps with initial placement, then ensure you find and use the original woodscrew holes. I also marked where the trim hold pins were located to make refitting easier. Put in the woodscrews first as the threaded posts have a tendency not to pull the aluminium tunnel down onto the ply.