[2] George Seton, 7th Lord Seton is thought to have commissioned dies from Gilbert to strike gold and silver medals with the motto "UN DIEU, UN FOY, UN ROY, UN LOY", and a monogram with his initials and those of his wife, Isobel Hamilton, daughter of William Hamilton of Sanquhar, "GS-IH," with another motto "Nemo Potest Duobus Dominus Servire," from Matthew 6:24, "No one can serve two masters".
[4] By May 1566, Gilbert was appointed as the master goldsmith to Mary, Queen of Scots and Lord Darnley, and he was exempted from any military service that would take him away from his royal duties.
[5] On 11 June 1567, the Provost of Edinburgh, Simon Preston, sent Edward Littil, William Foular, and Gilbert to Dunbar Castle, where Mary was with Bothwell, with the burgh council's excuse and reasons for receiving their political opponents, the Confederate Lords.
[8] He went to London with the merchant William Fowler in May 1571, bringing letters from Mary, Queen of Scots to John Lesley, Bishop of Ross.
Morton was persuaded to support the "liberty" of the craft incorporation, and soon after Hart accepted that he should make a "masterpiece" in the workshop of Heriot or William Cok.
Gilbert advised a committee on this gift, but the silver was made by other goldsmiths including Edward Hart, Thomas Annand, George Heriot, Adam Craig and William Cok or Cokky.
His nephew David Gilbert was commissioned by William Fairlie to remodel a jewel presented to Anne of Denmark during her Entry to Edinburgh.