David - yes I realised that I'd picked the wrong marriage (should have checked for them but as usual tend to be in a hurry) - however the posted age of infirm Isabella matches a strange bapt in the Kk Patrick bapts that I never resolved - suspect the Isabella Quirk als Sayle is in another John Quirk household in 1841 - there are a couple of unidentified John Quirks buried in Kk Patk pre 1851 that may be him.