World Family Tree # 5738 states he died after 1744, but also claims he moved to Russia in 1770. Also states he moved his trading company to Glasgow in 1750.
Robert was involved in the Northern Trade with Scandinavia and Russia. One of his sons married and settled in Moscow. After amassing a fortune from iron mills, this branch of the Magills became benefactors of Magill Foundations, homes established for the aged and orphans (Ziebarth, John. Direct conections : Ziebarth-McGill ancestry. New York : Ziemag Publishing, 1997, pg. 83).