J54 Sport Hood Information

I've been looking for a '71 Demon or Duster. In my search I've come across a lot of nice cars with nice options. Haven't pulled the trigger on anything yet but of all the cars I've inquired about none have been coded for the J54 Sport Hood option.

I know you see a lot of cars with this hood but it is added. I doubt there are any hard numbers as to how many cars were optioned this way but I was wondering if anyone had any guesstimates as to how many cars came optioned this way? Like I said, for as many as I've looked at none had the J54 option.

Also, anyone have any pictures of the underside of a J54 optioned hood?