We live in the same village, and my son has just got into Skinners with a combined score in his 11+ of 407.
As the cut-off for Skinners was 404, this shows that the geographic criteria was probably only used for scores right on the cut-off. I'm sure the school would be happy to let you know such info. However, these things change year-on-year but I think you would be safe where you live. However, there is definitely risks with TW Boys, so not the best first choice if you live further out as you may lose out altogether.