Danny
I'm glad to be able to tell you you're wrong regarding flying Hurricanes. The BBMF have two and in total there are around a dozen worldwide which is more than at any time in the last fifty years or so.
What you describe as the old small canopies on PT462 is the design the late Nick Grace came up with for ML407 as mentioned in Ricardian's link and afterwards used on several of the other survivors although at least one has since reverted to the original pattern.