For the moment, this "gentleman" is a dead end.
I know from his will that Herbert CLARKE had a brother Jonas, a sister Elizabeth HARPER, both dead by March 1807. He had a wife Elizabeth (presumably PUTNAM, married 15 Jan 1758 in St. Clement Danes), also dead by March 1807.
His children were:
Sarah, married Thomas KING 1795, cheesemonger (some of their descendants are known);
Mary chr. 1768, married Thomas BENSLEY jr., printer (descendants known);
probably Elizabeth 1767 and Francis 1770;
and perhaps others.
I know he was a manufacturer of buttons, and lived in Drury Lane, London. He died wealthy, had a house in Uxbridge, and asked to be buried in Hillingdon.
From London Lives I know the name of one of his servants, the way he voted, and how much he insured his houses for. I have quite a lot more details, BUT...
what I don't know is who his parents were, and when and where he was born.
Herbert was an uncommon name in the 1700s, so may be a family surname.
Any other descendants out there, who might have more information? Or any thoughts of how/where to search next? (I'm in rural Canada.)
Thanks--J. Elderfield