Danny - if the list that Daf Hucker has posted a link to is still current, that situation is still the case (officer metal on collar, NCO cloth on sleeve). That is why I wonder what the metal A above the sergeant's chevrons that the OP talks about signifies.
To all those disparaging this document - I made a living out of flogging this sort of stuff for 30 years or so, so don't knock it. Very useful! The army ones are fascinating, and the navy seems to invent a whole new set of trades every couple of years or so, each with its own particular sleeve badge - runs into hundreds.
brokenlink - there is a continuous downward trend in the quality of badges etc. I collect military buttons and I have a complete set of all 109 pre-1881 buttons from the old numbered regiments of foot. All are of superb quality and some are works of art. No comparison with modern anodised junk.