I stand corrected. The Postboxes etc in Scotland don't even carry the reginal name. Just the Scottish Crown.



Here's a bit from a article about it all: The E II R issue was debated in the House of Commons and even in court, but attempts to challenge the Queen’s right to be declared as Elizabeth II across the United Kingdom proved to be unsuccessful. A further statement by the Crown would declare that the Royal title of the new monarch should reflect the highest number from either the Kingdom of England or the Kingdom of Scotland. However, the bombing incident had caused significant distress among Inch residents, who made it clear that any future erection carrying the E II R identification would not be welcome. To avoid any further troubles Scottish pillar boxes, mail vans and other post office paraphernalia would carry the Crown of Scotland from then on.

https://www.scotsman.com/arts-and-culture/lost-edinburgh-queen-and-exploding-post-box-1527366