Linemar Co was a manufacturing and import company for Louis Marx & Co. They are sometimes referred to incorrectly as Line Mar Toys due to the trademark used. Information sources indicate Linemar was in business from the 1950s to approximately 1970, when the company was absorbed into the Louis Marx & Co parent company.
It appears the Linemar branded toys were available from the late 1950s, with the diecast vehicles being sold in boxes similar to the early Matchbox style, under the name "Elegant Miniatures". The range of vehicles included cars from the 1950s and commercial vehicles, said to be in the approximate scale of 1:90, however the Euclid #5 truck comes in at approximately 1:160 scale. The #88 Murphy Special Racer comes in at around 1:84 scale.
The cars included both American and European cars and race cars, while the commercial vehicles included construction vehicles, tow trucks, pickup trucks, and even a Landrover!. While some say the commercial vehicles were primarily construction equipment, I have found evidence that aircraft, helicopters, farm equipment (tractors), and military vehicles (tanks, etc) were in the "Elegant Miniatures" range.
A second range of castings in approximately 1:60 scale, called "Collectoys" was released circa 1960. These were also made in Japan. This series also comprised both American and European models with many castings being similar to Hubley Real Toys and about 3.5 inches long.
A 2nd range under the "Collectoys" name is described in some references only as "small plastic vehicles from the 1960s". With the wonders of the internet and my personal collection, I can confirm these are plastic diecast vehicles, some of which were previously issued in diecast metal as "Elegant Miniatures".
Linemar also produced mechanised toys. Some of their earliest offerings featured the Hanna-Barbera cartoon series characters in lithographed tinplate. These were released in the 1960s and featured characters like Huckleberry Hound, Yogi Bear, and Quick-draw McGraw, at the wheel of a car, go kart, aeroplane, or as hopping windup figures. They also produced a range of tinplate toys based on Disney characters.