I can't answer your sizing questions with any confidence, as Grenson's have weird sizing to begin with, and I'm only familiar w/C&J's 325 last. I can tell you that the Church 8E should fit a narrow US size 9 foot (E is narrow for church's).
These are the same shoe as listed in herringshoes for 340 pounds (about $570). The brogueing pattern might be a touch different, as the ones i have are basically new old stock (before prada), and the pattern, to my eye, looks slightly different.
Anyway, these are on ebay now with no reserve.