I joined in 1987 which is when I first remember Caxtons.Carsons came in a blue wrapper... came in tins in the old 10 man ration pack., don't know when you served though Carsons disappeared from rations in the mid to late 1960s last I saw a bar was in Libya 1967 - presumably because stocks were exhausted.
Never heard of Caxtons - what years was that brand around?
I'm not a ration buff... I was infantry - just ate them!
I first recall seeing OP chocolate in the ration packs a couple of years later