Hi Julian,
I have some info which may help you,
George Havelock 1688-1749 Clock maker married Mary Barry 1704-1766
Marriage Guisborough 6th Jan 1754
William 1728 Guisborough died 10th Oct 1777 Sunderland shipbuilder, married Anne Longbottom 1728 Sunderland her father Jacob Longbottom
Children
William 1756 2nd Dec. Sunderland died 24June 1836 Hievetree Devon, maried Jane Carter 16th August. 1787.Bishopwearmouth
Jacob 27th Dec 1758 Guisborough Died 7th July , 1825 Guisborough, married Margery Postgate
27th May 1795 Guisborough
Mary 1760 died 1823 married Ralph Wheatley1776 Sunderland Parish church
Dorothy 1761 married Wiliam Huntrods 2nd Sept 1794 Bishopwearmouth
Thomas 20th April 1763, Guisborough died 8th Oct 1845 Darlington Durham married Sophia Louisa Martin 1786
Hannah Nov 1766 Sunderland died 9th Jan 1837 Darlington Durham, married Robert Allen 20th Dec 1792 Newbottle second marriage spouse not known 20th may 1804
ANN HAVELOCK 1770 Sunderland died 5th Sept 1855 married JAMES LEE 8th Jan 1803 Bishopwearmouth
Sir Henry Havelock of Lucknow fame was the 4th child of William 1756 and Jane Carter 14th June 1769 Yarm Yorkshire ,Henry was born 5th April 1795 Ford Hall Durham.he died 25th nov 1857 Lucknow, Alimbaga, India.married Hannah Shepherd Marshman 9th Feb 1829 Scrampore, Calcutta.
My 8th greatgrandfather was George 1726 Guisborough the Clock maker,he also had a son George 1726, also a clockmaker, he married Sarah Walker,1747 Guisborough
If I can help further let me know.
Regards Margaret