Islip church is dedicated to St Nicholas, better known as Father Christmas in the UK! One or two web sites say that Islip is the birthplace of Edward the Confessor, but that is the Islip near Oxford.
Why did John Bennet want a pilgrim to go to Islip? It is unlikely that it was for St Nicholas. I originally thought that he wanted to leave an offering the image of John Schorne, a popular saint, who is recorded as being there. But the will states,
To St Thomas Islippe 4d and to offer 1d.
Presumably St Thomas Becket. Never mind. The story of John Schorne is also interesting.
John Schorne was a rector of North Marston. He created a well during a drought that can still be visited, but he was better known for conjuring the devil into a boot, which is how he is usually depicted. Some say that this represented his ability to cure the gout of his petitioners. Schorne became famous, so much so that his body was acquired for St George's Chapel at Windsor Castle.