Hello Jimc
Be honest now, if you had been familiar with the naval term 'dress overall' in the context of a warship flying the correct flags on a ceremonial occasion would you have gone for the generic 'bunting' rather than the specific 'overall'?
Warships don't 'dress overall with bunting' as you say, they just 'dress overall'.
I've had a word with the crew here and we're all willing to put good money on this if you're interested.
As to pedantry, isn't that why we're all here?