Studio Jug marked H and P

Any ideas anyone

It's a long shot but Harding and Palmer Northumbrian Craft Pottery keeps popping into my head and in the absence of any other suggestions might be worth a try

what sort of glaze is that Ed?

had a look at harding & palmer , they don't appear to have those seal marks I also think this is a much older jug than their pottery , Dan - I really don't know what glaze it is , I guess somewher between ash and celadon if that makes any sense .