He entered marks at Goldsmiths Hall from 1812-23 as a watch case maker from 41 Rawstone Street, Islington.
Christening records at St Mary, Islington in 1815 for Henry and Richard, sons of John Harris watch case maker and his wife Rebecca show their address as previously as do the christening records for five more of their children at St James, Clerkenwell from 1820-27.
He entered another maker's mark from 22 Gloucester Street, Clerkenwell in 1835. This had been the address notified to Goldsmiths Hall by the watch case maker William John Hammon (Grimwade 328, 352-3) from 1834-35.
The 1841 UK Census for that address shows John Harris aged 70 years continuing as a watch case maker.
No clearly related death record has been found for him but the 1851 UK Census for the same address shows Rebecca as a widow living with her sons Alfred a watch maker and Henry a watch case maker.