We must be cousins. My grandfather William Oswald Cudworth was the nephew of Rachel Mary. I have just recently started research into my family history and started a website for this at http://holdent.tripod.ca/http://holdent.tripod.ca/ . There you will find a PDF replica of Joseph J. Green's "Some Account of the Family of Cudworth of Yorkshire, Lancashire, Etc., Etc., Particularly that Branch Settled at Sandal Magna, Near Wakefield, Co. York; and Darlington, Co. Durham", Headley Brothers, London, 1898. On page 50, begins a short account of Rachel and Brightwen Binyon, and their offspring.
About 20-odd years ago, I met in York the architect Bernard Fieldin who is the son of Olive Binyon and Humphrey Fieldin, according to my mother, Helen Elisabeth Cudworth. I would be interested in exchanging more information with you.