C mark stamp on matt speckled glaze vase

Hi,
Struggling to match this C stamp monogram to a potter. The vase shape is slightly uneven from handling prior to firing. The stone grey glaze is speckled and the rim has bare areas showing a terracotta coating beneath the grey glaze. The C monogram might be a G perhaps.
Any comments appreciated.

Difficult to make out if it s a C or what! There are two potters that use a C on its own. Clare Sutcliffe and Joanna Constantinidis. Not Constantinidis style. Clare Sutcliffe was trained at Wenford Bridge so might possibly be style.But unlikely.