George Dundas in Newbigging was factor for crops 1671-1678, though for most of the period Robert Russell acted as agent for the estate for the lands of Blairmucks in Lanarkshire, an office which he retained after the termination of George Dundas`s factory. Dundas was succeeded as factor by William Lockhart (crop 1679), William Ker (crops 1680-1681) and William Somerwell (crop 1682). The fragmentary nature of the accounts for crops 1683-1684 makes it difficult to deduce the arrangements for these years, but it seems probable that the laird himself managed the estate. Certainly, by July 1685, Somerwell is described as `late factor` and there is no evidence of a successor (Adv.MS.80.2.9, folio 214).