I've found several directories and extracted any 'Blackmore' entries and put them on https://sites.google.com/site/blackmoresite/
If you know of any interesting directories please let me know.
Look for the two pages with entries from these directories:
• Cambridge University Alumni, 1261-1900
• Alumni Oxonienses: The members of Oxford University 1500-1714
• Alumni Oxonienses: The members of Oxford University 1715-1886
• Dublin Apothecaries, Dublin, Ireland, 1791-1829
• The Universal British Directory of Trade, Commerce and Manufacture, Volume four, 1794.
• London City and Business Directory, London, England, 1805Post Office Annual Directory of London and Parts Adjacent 1814
• Gye's Bath Directory, Bath, England, corrected to Jan. 1819
• Gores' Liverpool Directory, Liverpool, England, 1825
• Gores' Directory of Liverpool, England 1827
• Exeter Itinerary and General Directory, Devon, England, 1828
• Bankrupt Directory: being a complete register of all the bankrupts with their residences, trades and dates when they appeared in the London Gazette: from December 1820 to April 1843.
• Post Office Directory of London, England 1841 Vol. 1
• Post Office Directory of London, England 1841 Vol. 2
• Montreal, Quebec Canada City Directory 1842
• Thom's Irish Almanac and Official Directory, with the Post office Dublin City and County, 1850
• Slater's Royal National and Commercial Directory, 1852-53
• British Medical Directory for England, Wales and Scotland, 1854
• Post office Directory of Berkshire, Northamptonshire, and Oxfordshire; with Bedfordshire, Buckinghamshire and Huntingdonshire 1854.
• Chicago, Illinois USA City Directory 1855
• Thom's Dublin Directory 1861
• County of Bruce (Ontario), West Canada, 1867
• Joint Stock Companies' Directory for 1867
• Post Office Directory for Gloucestershire, Herfordshire and Shropshire including the city of Bristol, 1863.
• Boston, Massachusetts, USA 1864
• Webster & Co.'s Directory of Bristol & Glamorganshire, 1865
• Crockford's Clerical Directory for 1865
• Michigan State Gazetteer and Business Directory for 1867 (USA)
• The Commercial Directory and Shippers Guide, 1872
• History, gazetteer and directory of the county of Devon: including the city of Exeter, England, 1878
• The Post Office Directory of Birmingham, England, 1879
• Kelly`s Directory of Hampshire, with the Isle of Wight, Wiltshire, and Dorsetshire, 1880.
• Kelly's Directory of the Leather Trades 1880
• Farmers’ and Business Directory, for the Counties of Carleton, Dundas, …and Stormont, Ontario, Canada 1886-7
• Prince Edward Island, Canada, Directory for 1889
• Philadelphia, Pennsylvania USA Directory for 1890
• Farmers' and Business Directory for the Counties of Dundas, Glengarry, and Stormont, Ontario, Canada 1891.
• Denver, Colorado USA City Directory for 1892
• Western Ontario Gazetteer and Directory for 1898
• Business and Professional Directory for all Cities in Ontario 1899-1900
• Polk's Toledo City Directory, 1899
• Manitoba and North West Territories, Directory for 1905
• Ottawa, Ontario Canada Directory for 1909