Thank you all for your help and suggestions. There are just too many Weston millers and too many Johns! There may be something to the Lucy Upton theory, as John named a daughter Lucy. He may also be the same miller listed on the last site sent to me, as he was at Lewes in 1841.
Just for the heck of it, his death information:
Death certificate...He was 78, died at the Dicker, Hellingly, formerly a farmer at Chiddingly, died of heart disease "years", certified, informer was Henry Wenham, in attendance of the Dicker, Hellingly.
Newspaper account:
We regret to announce the death of old and respected inhabitant. Mr. John Weston, of the Dicker, aged 78 years. It appears, upon inquiry, that the deceased was in the act of undressing himself, last Sunday night, the 14th inst.. and while stooping to take off some of his garments he suddenly fell and was instantly corpse! It was not considered necessary to hold inquest, he having suffered for a considerable time with disease of the heart, and his medical attendant having cautioned him against stooping, least such posture might accelerate his end. His remains were followed to the grave by a great number of relatives and friends. (Tuesday, 22 Apr 1861, Sussex Agricultural Express)
Sadly, no actual names of his relatives at the funeral. John was in Warbleton 1861 census yet died a few days later in Hellingly. The age is a little off, too, I think I need to find out if this is actually "my" John.