The Marown Parish Burial Register put out by IOMFHS has the same information as on Brian's site--i.e. John Gelling 21 years buried 17 May 1841'
Hopefully, someone can look at the parish register film.
IGI has a John W Gelling ch 19 SEP 1819 Marown
Father J Gelling
Mother M Fayle
Don't know anything about this group myself.

DJD