At Durham Records Online there are 20 baptisms for Tanfield St Margaret where the abode is 'Isle of Man'. The earliest is 1805, and the most recent is 1850. In these records the fathers' occupations are labourer, banksman, pitman.
The main group of baptisms starts in 1829 and the recurring names are Armstrong, Hunter, Wilson, Shield and Peacock.
e.g. 31 January 1841, William Newrick Shield, of Isle of Man, son of William (pitman) and Elizabeth Shield.
In the 1841 census the enumerator's route is:
Shield Row [many households]
Havannah [6 households]
Isle of Man [3 households]
South Moor [many households]
For 'Isle of Man' the heads of household are
John Armstrong, 43, banksman, born in county
William Shield, 40, coal miner, born in county
Thomas Davidson, 40, ag lab, born Ireland
(the total headcount for Isle of Man residents is 26; there are several others lodging with these three large familes)
Added:
In the 1851 census it is recorded as "Isle o' Man", with three households:
George Robinson, 46, coal miner
Thomas Peacock, 27 ag lab
Robert Anderson, 50, coal miner
all born Co. Durham