Interesting italics again today!!! 
I'm still pondering it; don't want to suggest anything in case I'm embarassingly way off the mark. I'd rather hear other people's theories

I had a quick look but was unable to find either Emery Hill or Margaret Patten. I do have my doubts about her age at death. 
Yeah, it's obviously unreliable - it would break all known records if it were accurate. I guess back then they didn't do as much checking. Would be interesting to see if it tallies with the birth certificate if it can be located (in which case both are wrong.)
Christ Church, Westminster was destroyed during the war and subsequently demolished, which is a shame as it looks quite imposing from the drawing on the web page.