There are a very few people at the time who are known to have lived into their nineties (nowadays, of course, not uncommon; my great-grandmother lived until 99; my mother is 95). One of the many changes is adequate heating in winter; until quite recently cold weather was known as "the old people's friend" because it carried people off before they got Alzheimer's and all the other nightmares of modern old age. Remember: few people in even late Tudor times (when your alleged John Parrott was born) had any glass windows in their houses. Almost no-one had all their windows glazed. And I doubt whether glaziers were among the early immigrants to America.
Someone on the LDS site has simply put two or three John Parrotts together; as simple as that. A 51-year-old is unlikely enough to have gone to a new life in Virginia: he probably had a normal life expectancy of around 9 years if he stayed put; and Virginia was a place which left you without energy for a year or two while you got used (or not) to new biotics; i was a place for young people and a gamble at that.
I don;t know when the first Quakers arrived in the New World, but how could a Perrott in Virginia have been converted to Quakerism between 1647 and 1662, and then decided to wander off to Barbados in 1662 aged 80? If Virginia carried risks even for young people, then the Carribean carried even more risks - yellow fever, God knows what else. New people without built-up immunities died, in droves. A new 80-year-old (how would he have suppported himself?) would have stood little chance.
Among the other things that you assume are the same as today is the disease risk. Did you know that over 50% of British soldiers sent to West African forts in the eighteenth century died of disease in their first year there? The sailor's rhyme "Beware, beware, the Bight of Benin/ One came out where forty went in" may have been an exaggeration; but not all that much so. Of course our viruses and biotics were more dangerous to native populations over most of the world than theirs were to us; but all the same, the danger went both ways.