A very belated thankyou, David, for filling the gaps.
Still at Brentford: https://www.shipspotting.com/photos/3681782

Completed April 1958 at Fairmile Shipyard, Berwick on Tweed (yard 477) as TARWAY, a liquid tar carrier for South Western Tar Distilleries, Eling Wharf, Southampton, working as far as Channel Islands; 1978 sold to Belsize Boatyard and work started on conversion for Irish Govt contract, but fell through; c.1979 sold to Teignmouth Harbour Authority, lengthened to 25.1m loa with 5.21m beam and 2.2m draft and converted to sand dredger/carrier, 80 tons gross, 120 tons dwt; 1980-96 reported owned or managed by Pike Ward; by 2006 operating as aggregate dredger between, Isle of Wight and mainland for local Solent owner; later reported sold to Spanish owner, but sale fell through; by 2009 at Maldon renamed STARWAY; 2011 again resold, renamed TARWAY and conversion started to houseboat now based on Thames at Brentford; Listed on National Historic Ships Register no. 3757.