He was Richard, the son of Joshua Johnston of the Clothworkers Company and sword cutler of Blackmoor Street, apprenticed to his father in 1780.
Thomas, the son of Joshua Johnston, sword cutler of St Clement Dane’s was apprenticed to Richard Johnston of the Clothworkers Company in 1795.
James Johnston was made free in the Cutlers Company in 1800 by servitude to (his brother) Richard noted in the document as a cutler.
Richard is listed in the 1806 London Poll Book as a sword cutler at 68 St James Street.
Richard Johnston, perhaps his son, is listed in the same trade at the same address in the Poll Books of 1834-37.