Antique Plate ID - Possibly English ?

I'd be grateful if anyone were able to identify the maker of this plate. It measures c. 24cm in diameter and is possibly from the late 18th to early 19th century (?).
I assume that it is European, possibly English.

It's a bit of a long shot, as the only mark is a blind stamp of the initials GM.

Thank you for any help !

 

I Love the colors!!! The third photo down however, makes it look like applied decals or a large cut out decal, however lovely it IS!!! Not saying I'm correct, either!! Even applying the decals would have been a bit tedious, I would think!!!

 

Agreed. I think older plate used as a blank.

 

I would like to have one of those plants that grows different species on the same branch... Really lovely plate!