Thank you very much for you message to Ireland Reaching Out.
Have you checked the follwing documents for possible information about George O'Neill, the bricklayer?
1820 J. Pigot, Commercail Directory of Ireland PRONI, NLI (Ir.9141 p 107)
1824 J. Pigot and Co., City of Dublin and Hibernian Provincial Directory, NLI
1834 Pettigrew and Oulton, Dublin Almanack and Official Directory, NLI
1844 Alexander Thom, Irish Almanack and Official Directory, NLI
1846 Slater's National Commercial Directory of Ireland, PRONI, NLI
This is just a small sample of the available directory's out there. PRONI stands for the Public Records of Northern Ireland. NLI stands for the National Library of Ireland.