I think it is almost certain that the profile for John Dunaway has been incorrectly linked to William Dunn and Joanna Marson, as his parents. Apart from the name change, there is also the fact that William Dunn appears to have lived in Kingswinford, Staffordshire, and John Dunaway born in Bosham, Sussex, though both of those places will have to be confirmed with reliable sources.
The image of the gravestone on FindAGrave cited on John Dunaway's profille, looks like he died aged 17, so is possibly not the same person as John Dunaway, born in 1785.