yeh! Duraglit was addictive as a 12 year old! Brasso smelt like dog wee! I too remember the button guards and buckle strip protector and of course I went on to serve in the Army Air Corps so still had a few years left of polishing the same things!
Neil, workshops that deal with stainless steel polish to various grades of finish from bright to quite a ground looking finish so that might be another possible option.
Melvyn Rutter or Life's motors might also have some thoughts and Holden are always doing classics up to original spec so a chat there might not be a bad idea.