Looking at the list there were less than 50 when the poem was published in 1898 but maybe when it was written there were 50 Wrens still standing? Some were demolished in the late 1800s and I wonder if one or more were in the process of being 'redeveloped' when ACD wrote the piece. Hence the thought of a sacred site or fane rather than a standing church? I suppose we will never really know. Still, thanks again for the input.

Cheers

DeG