not sure where you got your 'southern IoM' info from(a phrase that could not have some from a Manx source) - it is wrong as even a cursory glance at the 1851 census shows and as Moore states "It is much commoner in the North than in the South of the Island"

There are several contenders in the 1851 census - do you have any info on siblings, parents etc, date of emigration - 17year olds don't normally emigrate on their own unless there is family at the destination