Cpl Derek Humphries MM collecting his award at Buckingham Palace in the 50,s

A Question has been put to me why was Cpl Derek Humphries wearing a service cap not a beret and hackle when when being awarded his MM at Buckingham place l am trying to load a photo of wearing the said headdress but don't know how to attach a jpeg photo to this thread
Yours Aye
BennytheBall

Benny, I think the answer is if he was wearing Formal Ceremonial Number 2 Dress, then the correct head dress at that time would have been his Number 1 and not a beret, though stand to be corrected.

Cheers Dave.