Saz, welcome to the board, and thank you for adding more about Ambleside Pottery. I would love to see more of the pieces produced there if you have pics you could share with us please? Even though I live in Cumbria I never see any Ambleside Pottery amongst all the stuff I see at boot fairs and charity shops, which is disappointing for someone trying to find out what they made.
Were your grandfather and father potters elsewhere before they bought the business? It's always interesting to know the background as often there are similarities or influences from the pottery where a potter learned his or her craft.