Dragon-in-Compartment Chamberlain Worcester Armorial Cup & Saucer

Chamberlain Worcester porcelain dragon-in-compartment pattern armorial cup and saucer c. 1800 - 1810. 
 
Dimensions: Saucer approximately 5” diameter.
                        Cup approximately 2½” high
 
Decoration: 
Both the cup and saucer are decorated in the Dragon-in-Compartment pattern of gold, red, green, and blue. Each has a painted “Chamberlain Worcester” on its base.
 
The cup bears an unusual Scottish armorial. The motto: “Sub Sole Sub Umbra Virens” is that of the Scottish clan Irvine.
 
The crest is of a different family and may be that of the Scottish family Ochterlony that intermarried with the Irvines. However, the Ochterlony swan is supposed to have a gold chain and be charged on its breast with a rose. I have also been told that, the crest may be that Campbell of Cawdor, Lindsay, Wemyss, or Edmonstone.
 
As noted by The British Museum regarding another armorial early Worcester piece, the Worcester painter/enamellers of that time often didn't get all the details right.
 
The saucer is unusual because instead of the typical central rosette, it has blue flower.
 
Condition: The cup has a hairline; otherwise in excellent condition consistent with age and usage.