I posted this on Rootsweb and Ancestry and thought I'd better post here as well.
Our Kinghorn line is mostly out of Midlothian and Fife.The direct line going back is from:
George Wilson Kinghorn, b: 1910, Edinburgh who came to Canada via NY, 17 Oct 1919 (apparently an aunt went to Australia with her husband and wanted George to go with them so their is a possible relationship to Australian folks);
George Stevenson Kinghorn, b: 1882, Leith, Edinburgh married Jemima Penman Wilson, 1907, Edinburgh, d: 1918, Belgium;
William Kinghorn, b abt 1851, Kirkcaldy, Fife married Janet Johnston Stevenson, 1880, Prinlaws, Leslie, Fife, d: 1925, Yoker, Renfrew;
William Blackwood Kinghorn, b: 1820, Dunfermline, Fife married Janet Young, 1843, Abbotshall, Kirkcaldy,Fife, d: 1895, Ladybank;
James Kinghorn, b: 1785, Limekilns, Dunfermline, Fife married Jean/Jane Melvill(e),1812, Eding, Dunfermline,Fife, d: bef 1857, unknown location;
John Kinghorn, b: 1746, Auchtermuchty, Fife married Euphan Dewar, 1775, Pitliver, Dunfermline, Fife;
William Kinghorn, b: 1715, St Cuthberts, Edinburgh married Isobel Johnstown (her parents James Johnstown and Isobel Ritchie), 1774, Auchtermuchty, Fife.
Then it gets iffy....John Kinghorn, b: abt 1674, married Margaret Cleland, 27 Jan 1709, at Kirkliston, W Lothian & Midlothian; then it looks like this John born abt 1674-1684 depending on his age at marriage, may have been son of Thomas Kinghorn and Margaret Wright, married 08 Aug 1674, Pencaitland, E Lothian, but there is another stronger claim to this relationship so it's up in the air and am looking for more confirming data.
Please contact me if you think we are connected to your lines.