Wondering further about any relationship between Blue Star Garages and Blue Star Line: they both use the same blue star as a logo, and this would presumably have been a Registered Trade Mark. if the companies were not related, the Registry might well have said they were too similar for unrelated companies to use. Likewise the name "Blue Star" would need to be approved by Companies House. Normally different companies will be refused Trade Marks and Names if they are too close to existing ones, unless they are in clearly different businesses, say Baking and Plumbing equipment.
Shipping and Motoring might have both been classed as "Transport" and therefore the Blue Star name and logo might only have been grantable if the companies were part of one group, and therefore not in competition or any conflict of interest.