Thanks, Rob and Jim.
Jim, where do you think the will could be which Shirley transcribed?
I don't know whether Brian's index ref was actually in the filmed index because I didn't record Braddan Corkill will entries. If not there Brian would have created the index entry to fit the details sent him with the transcript.
I've never compared the parish listings with the actual wills so I don't know whether they sometimes had omissions, but not sure what you mean by the will not checking out with the film number for that year? The LDS catalog had Arch wills 1705-1710 under film number 0106209. (Can't double-check the recent catalog online at the moment because FamilySearch has decided it doesn't like my browser.)
Sue