John Howell Rector in New Radnor 17c?

[Crunwere]

On Crunwere Church Pembrokehsire is a gravestone which reads:

Near this wall lies the body of John Howell A.M.
The son of Reynold Howell of Trenewyed, Gent.
He was sometime Rector of New Radnor but in the year of Trial 1691 was deprived of all that he could not keep with a good conscience.
Who died Jan. 17th 1727, aged 70.
(A stone tablet in memory of a non-juring clergyman)

Does anyone know of anything about this chap?  I have tried the vicars years ago and some other places but had no response.
(Trenewyed is actually Trenewydd in Crunwere parish.)