Arthur Grimwade presumed Thomas Townraw was dead or retired by 1773 as he did not appear on the Parliamentary list of that year. He did not appear on the list because he was no longer a working silversmith. Thomas Townraw had had taken up the position of Weigher at Goldsmiths Hall, presumably some time after 1753 when his third mark was entered. By 1764 he was described as the Senior Weigher at GH at an Old Bailey Trial, the content of which can be found at:
http://www.925-1000.com/a_OB_JonesBourk1764.htmPositions such as Weigher at GH were keenly sought after by those in the silversmithing trade as it was considered as a safe job, and GH were equally keen that such positions were filled by ex-silversmiths, for they brought with them a wealth of knowledge of the trade.