If Timothy does indeed descend from Nicholas, we have a gap in the family history of about 200 years, ie about 8-10 generations are missing.
From about 1820 the family became closely involved in the Norwich brewery of Steward & Patteson, which was managed by the families of the shareholders until 1963. A summary of the history of the brewery is included in the last section below.
The book "Norfolk Beers from English Barley - A History of Steward and Patteson 1793-1963" by Terry Gourvish contains considerable information on the family and much of the information here is drawn from it.
Gourvish references two sources (5 & 6) for his information on the family, hopefully finding these will throw light onto these gaps.
See the extract in the footnotes from "The Perlustration of Great Yarmouth". This confirms the story of the Stewards linking the Yarmouth family to Wells-next-the-Sea and also provides some fascinating insights into the family.
The arms confirmed to the Yarmouth family by authority are - quarterly or. and arg., on a fess sa., three fleur-de-lis of the first; in the first and fourth quarters a fesse cheque of the second and third; and in the second and third quarters a lion ramp. gu., debruised by a bend raguly or.; and for a crest, on a mount vert. within a crown valley or., a lion ramp. gu.
Rev Peter van Sarn
( - )
There was another brother, Thomas Harbord. Timothy and Hannah had a daughter, Hannah, who was married to the Rev. Peter van Sarn, and they had an only child, Peter van Sarn.
Another Harbord family, the Barons of Suffield, lived at Gunton Hall near Erpringham in Norfolk. The Hon Edward Harbord, barrister-at-law and MP for Yarmouth ca 1809, was the brother to William Lord Suffield, may be a link between these families.