Thanks for that info Kathy, especially the Whixley tip, after reading your reply Whixley looks very interesting. I did get quite a few Sturdys from the IGI but somehow missed the Whixley Sturdys, those I found were mainly St Peters, Leeds (loads) and Kilburn.
It did seem likely that the Thomas buried in Nun Monkton was related to Oswald but since there appeared to be no other info such as age attached to the burial entry for Thomas, it's down to guesswork.
Do you know where in Yorkshire the PRs for Whixley are held?
My wife and I are planning another visit to the UK around February 2006, hopefully to celebrate my mother's 100th birthday, I told her that she has to hang on until then

We will be staying with my mother in Essex, if I get a chance perhaps I can get up to Yorkshire to check Whixley PRs.