I'm wondering if he got married in same church....
if so is his name entered legibly by Priest/Minister ??
I've had a look through the marriages I've transcribed so far (1813-1829) and the Johns I've found are: Carder, Bradshaw, Cuthburt, Clark, Cole, Linsell, Hatch, Farrow, Kendle, Wilson, Philbrook, Cottis, Dunmour, Auger, Howard, Dowsett, Brown. None of which seem to resemble the signature in any way at all.
GEFFRY?
Possibly.... agree that it could be a G at the start, but can't be sure. Pretty sure the RY is correct.