Old Bricks, I remember wearing 5A for your Grad Ball, to which those of us who'd escaped to University were invited. I was staying overnight in Grantham and can assure you that trying to drive a car with a wing collar trying to cut ones throat is emphatically not to be recommended! Her ladyship of the time thought it most amusing though....
Perhaps another reason for the demise was that increasing numbers of oikish individuals had taken to wearing elasticated bow ties
, which could not be worn with a wing collar?