Is your John living in Camberwell in 1851 with wife Jane and son Alfred - HO107/1581? If so, he will be in Metropolitan Surrey for the 41 census.
In 1861 he gives his place of birth as Rushmere. There are 2 parishes in Suffolk with this name.
1 in Woodbridge RD, Carlford Hundred - Rushmere St Andrew
1 in Mutford RD, Mutford Hundred - Rushmere
Interestingly there is a marriage for a John Pleasance WOODTHORPE on the IGI at Rushmere in 1818 to Ann CRICKMAY, but this is not on the Suffolk Marriage Index 1813-1837 which is a more reliable source.
Some members do have access to Suffolk Parish Records so it might be worth asking for a specific Rushmere lookup on the LOOKUP REQUESTS board. It would also probably be worthwhile asking for a 41 lookup on the London LOOKUP REQUESTS board, if you do not already have this information.