Very interesting!
Blue Star was a chain of Petrol Stations / Garages / Motor Dealers in the UK which lasted into the 1970s.
They often sold Regent brand, later Texaco petrol.
There was a "Blue Star" very close to where I lived in Liverpool on Smithdown Road.
My father and grandfather always used to have their cars serviced there when I was young in the 60s and 70s.
This closed in the late 1970s, lay derelict for some time, before the petrol forecourt reopened as an Elf, later Total branded filling station in 1982 and still trades today as the Total Smithdown Road Filling Station.
The actual car workshops behind the forecourt were flattened and houses built thereon around the same time as the forecourt reopened.
A few years ago I acquired on of these houses and thus live on part of a Blue Star garage site!
I was aware of some "Blue Star" garages when I went on trips with my parents.
One of which I also became well aware of was near Hayle in Cornwall, close to the end of the current Hayle by pass andnot far from family holiday destinations in Penzance and St. Ives.
The is garage was then on what was the original A30. Part of the building still stands but is no longer a garage. When it was a garage I think it had a cafe attached.
This "Blue Star" I think sold shell petrol or did at least in its later years.
I am sure a few years ago there were some internet references to the former "Blue Star" - but can't, this evening find it.
John