George VI and Edward VIII

[neloon]

As I recall, one of the earliest (perhaps "the" earliest) written descriptions of the plaid was written as "pladd" or "pladde".

Not really - that came much later. The earliest references are

1510 "To dye 4 ells lie plaidis for my lord 2s."
1512 "In Air, for ane plaid to be the king ane coit"
1538 "An plaid of voll"
:
:
1597 "The Highlanders' predecessors vsed short mantles or playds of diuers colours but for the most part now, they use browne, most neere to the colour of the hadder to the effect, when they lye amongst the hadder, the bright colour of their playds shall not bewray them."
1630 "Their habite is ... a plead about their shoulders which is a mantle of divers colours, much finer and lighter stuffe than their hose."

Perhaps "plad" came to be an English pronunciation. By 1804, Lord Byron was writing "My cap was the bonnet, my cloak was the plaid [rime glade] . Note: this word is erroneously pronounced plad; the proper pronunciation (according to the Scotch) is shown by the orthography".



The early Scots spellings are a fair while ago and Scots wasn't/isn't pronounced the same as English.
I think we may be off-topic!

Alan