augarten or augarten fake?

Found this cup and saucer with a striped shield mark underneath which augarten used.
A second mark underneath the cup with the three letters "ERB" in a leaf shaped shield.
No idea who used this combination
Normally fakes come in low quality and out of the reason, that this portrait is finely handpainted, I'm not sure this is an augarten fake....
The Lady painted on the cup remind me of an portrait of Empress Elisabeth of Austria,
It is really a finely painted lady with a diadem or crown
I will go on searching informations