Mercury was a very well known brand in 1:43, but less so as a manufacturer of smaller scale vehicles. They did create a series of "Speedy" cars in the sixties, followed by "Speedy Velox", different in that the Velox has "Speed wheel"-type wheels, instead of the original Speedy series, which has rubber tyres and hub-type wheels. Later, towards the end of Mercury in 1980, they created the Mercury Micro-series, which was cheaper (or possibly, cheaper still) then their Speedy Velox predecessors.
This is one of the original Speedy-series cars. It depicts a Mercedes-Benz C111. The windowslook a bit opaque, not sure if this was intentional. By the looks of others cars in the series, I would say probably not.
This van, a Fiat 238-van, is somewhat rarer. This version is the schoolbus-version, other versions were also available, though they seem rare. This particular van is either missing a rear hubcap, or this is an "error".
This is one of the later "Speedy Velox"-series of cars. I can find little documentation on this particular Europa.One can see the somewhat higher "speed wheels", which makes this car and others in this series look somewhat awkward.
This is one of the last series, Mercury Micro. This particular vehicle is a Fiat 697 truck, which was made in different versions. It is in typical "3 inch"-fashion made to fit the box and is therefore smaller in scale, more like 1:87.
Some more cars of the Mercury Micro-series (top to bottom): Fiat 131 Abarth, Lancia Stratos, Fiat Campagnola, Fiat 127. I hope I can add another car to my collection. If I do, I will post it here.