Thank you Kerry so much for trying to help find John Oliver.
I have all the census records for him, and the 1851 says 'Where born... Mayfield'.
If his wife was the one who gave the information she may have been 'out' by a village or two!
If there are lots of Olivers in Heathfield at that time it is worth considering.
One other pointer is that one of his daughters was b. in Heathfield, which I have thought may have been the family going there to family for the child's birth.
We have his death record - Feb 1884- aged 75years, which makes his birth year 1809.
Thanks again,
Annette