Thanks one again Roger. Since my daughter works for Historic England, I really should have found that reference myself, but thanks for pointing me in the right direction.
I presume you know that the Tiverton Museum holds many of the records of Heathcoat's company. Unfortunately for me, I think my ancestor was probably a journeyman, and therefore paid by the day. If he had been an employee, he would have appeared in the company records, which he doesn't.
Some years back, my wife and I visited the museum and arranged to talk to a retired employee of the Heathcoat company. He said that when he was a young apprentice, he remembered talking to older employees who had, in their youth, talked to some of the people who were involved in the exodus from Loughborough to Tiverton in 1816. So it doesn't take too many generations to span the years back to 1816.
Thank you again for your help - much appreciated.
Best wishes,
Mike