M.O.R. - I do not have a penchant for picklehaube helmets even for non-motorcycle use.

I still cannot accept your premise that someone who is 100% "correctly" dressed somehow magically vanishes into the background or that someone who is 90-99% is somehow ridiculed. Whereas one may regret relaxations in standards of formal dress from a more elitist "good old days" our more egalitarian age views what is dressy in a different way.

I am glad you are able to get BBC4. I do not know what the dress standards of Japanese Court etiquette are but from what I have seen, the Imperial males are more likely to be seen in western clothing. Hirohito after the war is usually seen in Morning Dress with frock coat and striped trousers. HMQ may have had the option of a kimono for all I know. When she has called on the Pope in an official capacity she followed an apparent convention for a black dress and veil for a non-Catholic Sovereign but it has modernised since earlier such visits to previous Popes. A demonstration of how conventions get adapted over time perhaps?