There was a period when the 4/4 only had side vents as standard, but I seem to remember that top louvres were available as an option. The Michael Palmer book "Morgan 4/4 The First 75 Years" has a couple of pictures of cars with the top of the bonnet uncut.
I wonder if the option was charged per slat?
~iw
(Hmm, when I read this back I seem to have an adenoid problem!)
