Hello, 

I collect sea glass and sea pottery. I live in an area that at one time had a booming oyster industry dating as far back as the 1600’s  I often find shards of onion bottles, Pottery etc  the area was occupiedby British loyalists during the revolutionary war.  I wondered if anyone is familiar with this mark  it may not be antique at all..appears to be made in England  any info would be appreciated!