Thanks Tom. 
I know the backstory of the Daytona Coupe and its improved aero over the open cockpit. At least the short version of that story anyway 
 
But are you saying that the FIA 289s ran on the European circuit at Le Mans etc with a hard top back in the day?  That I didn't realize. 
Who was making those hard tops back then? Probably not AC, correct? 
Like I said above, I have lots of questions about hard tops which I didn't realize were period correct.