This plate is a definite anomaly! 
 
Marked with pattern 44 but does not conform to the relevant sketch in the Derby Pattern Books for that particular pattern.  But there's more .....
 
According to Sir Stephen Mitchell's book "The Marks on Chelsea Derby and Early Crossed Batons "Useful Wares" c1770-1790" no item had been found carrying Gilder's number 6, thought to be the number designated to Edward Withers - until now.  Please study my photos carefully and note the small dot placed at the base of the "6" to avoid confusion with a "9".
 
The decoration is also most unusual, a blue-green rim featuring cloud shaped, gilded reserves of pink roses, interspersed with strange dark coloured motifs, along with central rose study - without doubt painted by Withers.
 
In good condition for its age - there is some overfiring visible in one area at the rim and a faint star crack towards the centre of the plate.
 
Marked with crown, crossed batons, dots and D in puce, with pattern number 44, and with gilder's number 6.