Hi, I've had a look through the Worle, St Martin's records and I couldn't see any sight of your Isaac Sayer. Most of the parish records for that area seem to start after the date you're interested in. Although the Portbury-hundred site says it has records from 1668-1800, it seems to stop at 1750. You could e-mail Mary mason wh0se site it is and ask for further help I expect. Hope you find what you're looking for Ros