I'm not going to immediately consign the anodised example in my collection to the collar draw! The date quoted, unless I've missed it elsewhere refers to a period before anodised was even introduced!
The Royal Anglian cap badge, despite belonging to a fine Regiment is probably on a list of one to one hundred of the British Army's most inspired cap badge designs, is probably somewhere in the ten thousands?
From the 50/60's to present date it is unlikely that cadet units whether public school or ACF have had any huge quantity of uniforms upon which collar badges would have been worn?
I would be tempted to do more research before tagging this as a collar badge rather than a badge introduced for wear in the beret in place of a boring Star thingy with a sandcastle stuck to it!
Andy