Hi Brian,
I think that info can probably be classed as 'dubious': the death date is correct but Ian has already purchased John's death certificate which shows him to have died in Heworth on that date, not Oldham. The mention of Trichinopoly looks interesting given the family connection with India but the date is out - he was born c. 1790 according to his age at death. It's the same with a lot of potentially intriguing info online unfortunately: without a source, it doesn't help much and can often send people off in the wrong direction entirely.
I'm still flying a flag for my suggestion of John being born at Romaldkirk in North Yorkshire in 1790, son of William Stephenson and Mary nee Layton. I have some circumstantial evidence for that (Layton as a middle name given to daughter Katherine for example) but not enough to stand as genealogical 'proof'.
Cheers,
Jon