Found this pic in an old book and wondered if anyone knows if they were a British company?
The Volvo N12 certainly looks to have UK plates on,but I can’t say that I’ve ever heard of the company.
One for Rikki perhaps…
TSL Vanguard Vehicle Services Ltd are based in Leeds - take a look at:- tslvanguard.co.uk/
Blimey!! they are a shaddow of what they use to be 
TSL started as Transport Services Lindsey, owned by Consolidated Land and run by George Curtis (later of G E Curtis fame) but later the name was acquired by Vanguard Vehicle Services of Leeds - a wholly different and unpleasant bunch
Whatever happened to Consolidated Land Services?
TSL were based on Midland rd in Scunthorpe, the Volvo N1233 6x4 was converted from a six wheel dump truck from new a lot of the work was carried out in there own workshops and nearby engineering companies. It was driven from new by Mick Crawshaw, top man at that heavy game, it ended its life as a recovery truck for Gallows Wood on the side of the M180 at Brigg.