Armorial porcelain egg cups?

Hi,
I’ve just acquired 2 lovely china/porcelain egg cups that I’d very much like to know more about .
They are not identical, but both are painted (extremely finely) with a coronet with 5 pearls and some kind of interlocking letters that I’ve failed to identify.
I thought it would be easy to find out via Google if it was a Baronets or an Earls coronet etc but I’ve drawn a complete blank!
I presume that these are armorial pieces?
Would be incredibly grateful if anyone could help me identify what these are.
Thanks!

Derby maybe? A base pic might help.

Thanks denbydump , can’t see any markings though….