This is the original image I had for the main building (the actual abbey) of Singer's Abbey. It's a model because that's what I was looking for in Sorceress of Faith -- Tuck's house.
I'm sure I pulled it off webshots (looks like the date is September 2005), but it's no longer there. So not only don't I know what church this is, I can't give credit for the photo.
The Singer's Offices, Audience Room, as well as another chapel is King's College Chapel in Cambridge, England (that's "seen" in Protector of the Flight). I have a jumble of buildings as the actual abbey.
Anyway, any help will be gratefully gushed over.
May you have your research at your fingertips.