Ginnie Harrison, nee Bamford, Tregony and The Sloop, St Ives

Its a bit late now I suppose,
But the date on the mug is 1978. The clay looks like earthenware. The Leach Pottery virtually gave up using earthenware in the mid 1930's.Completely by the early 50's.
So no. Its not a Leach mark.

I have just seen this thread, which is nearly 2 years old, after philpot gave an answer this morning.

It had been posted elsewhere rather than under the "ID My Pottery" thread and, as philpot states, "It's a bit late now".

I decided to move it to the correct thread to illustrate that if IDs are requested elsewhere they are less likely to be answered.

Maybe by a potter local to which ever school is mentioned on the front of the mug.

Possibly an early mark of Ginnie Harrison, nee Bamford, Tregony and The Sloop, St Ives. Unfortunately the Virtual museum of Cornish pottery marks only has her later handwritten GBH mark.