Hi Cas,
With your help - by George, I think I've got it!
It was with you saying Purley that made me think of Hurley. If you look at the 'H' at the start of 'Henry' 4 lines above, I think 'H' is the first letter of my mystery parish. I would never in a month of Sundays thought of it starting with a 'H' without your suggestion of Purley. I've also learned something else - the only Purley I knew of was the one in London.
Thanks again,
Jill