After having run the original Series One for three years, in mid-1960 Lotus launched the Series Two of their iconic Seven open-topped roadsters.

With its totally Spartan design being one of its key features, Lotus saw little reason in changing its external appearance, instead of concentrating on making a raft of changes and improvements.

The chassis of the Series Two was a slightly simplified version of the Series One, with a different "A-frame" type of rear axle location.

A relocated (Triumph Herald) rack-and-pinion steering took over, along with a Standard back axle, and 13in disc wheels were now fitted, this time around without an option to fit wire wheels.

The only visual difference was the Series Two Seven now came fitted with attractive plastic mouldings for the nose cone and front and rear wings, custom designed and produced in Glass Reinforced Plastic (GRP).

Almost all versions of the Series Twos produced in their seven-year production run came with flared and swept front wings.

The Series Two format remained in production till 1967, replaced by the Series Three.

Most Seven devotees regard the Series Three as the finest of the Sevens as it was the most powerful, fitted with a 1298 cc 79.3 cui engine, matched with a new all-synchromesh Ford gearbox.

This combination was capable of generating 75 bhp and reaching a top speed of 152 km/h (94 mph).

For those who were on the lookout for even more power, a twin-Weber 1500 could be specified, producing fully 90 bhp.

The new car's "base" clientele loved the higher performance they were offered, the S3 becoming the best-selling Seven so far.

By the late Sixties, Lotus seemed to be heading away from the design philosophy that was the backbone of the Seven, producing ever more luxurious hard top sports coupes.

In 1974 Lotus once again shocked the independent car manufacturing sector by selling off the Seven manufacturing rights to Caterham Cars.

Caterham wasted little time in reintroducing the ultimate Seven, the Series Three better known as the Caterham Seven. Production of this excellent replica version of a UK Sixties classic continues well into the 21st century.