No misprint Howard
The current building is just over 200 years old, but the Church is much older than the buildings that it uses.
The earliest record we can find of the Church at Eythorne is at the trial of Joan of Kent in 1550 (which is the date from which we number the age of the Church here) where she talks of learning the true meaning of Christianity as a young girl in Eythorne before being executed for her beliefs. So, clearly the Church at Eythorne pre-dates 1550, but by how much we don't know.
As religious views other than those sponsored by the Crown were punishable by death, the Church at Eythorne operated clandestinely for many years both pre and post 1550, so written records are rather hard to come by and dates are therefore not very easily pinned down.
Clearly, as early as the late 15th century, the Arch-Bishop of Canterbury was not happy about the growth of the theology that was taught directly from the Bible to ordinary folk without the filter of an approved priest in East Kent, but he was not specific about the geography when he referred to the nest of vipers recently sprung up in East Kent. So, rather than guess, Eythorne fixes on the earliest confirmed date.
The Church at Eythorne is one of the oldest surviving non-conformist congregations in the UK.