Hi
There are lots of George Simmonds deaths in the 1860's in Sussex and unfortunately - the index does not show ages at death until the late 1860's so it is difficult to narrow it down
Is he the 1861 entry b Trotton and living in Rogate in 1861 - wife Jane?
If yes - then the registration district for his death would be Midhurst and this is the only entry for that district
Deaths June qtr 1863 George Simmonds Midhurst 2b 231