Hi Simon,
It was a discussion I came across online years ago when sculpting a Para figure I released, I always assumed wings were worn on smocks as they are today. Since that discussion I have seen plenty of photos taken for Market Garden that show Para Reg troops without wings on their smocks which I initially took as Infantry Glider troops such as Staff's, Buck's etc.
Here is one example of 1 Para troops prior to Market Garden and you will see not all are wearing wings, I don't think it was a blanket rule as I have seen some with and some without but seems NCO's and above all did and Toms tended not to on their smocks.
I know prior to 1941/42 not sure exact date that insignia was only to be worn on Battledress but then rule changed to allow wings on smocks but maybe that changed again for Market Garden as Denison smocks were classed as camouflage items.
{Image added for discussion purpose only}
All the best mate
Steve
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