Imperial model 66 typewriter, 1957-1960, serial no. 6E79731. WIth interchangebale keyboards and typebaskets; mathematical Greek keyboard unit, no. 6F24738, mathematical English keyboard unit no. 6E80064. The serial number 6E79731 dates the typewriter to 1957-1960.

In 1954, the Imperial Typewriter Company announced a new desk typewriter machine, the Model 66, and an expansion of the company with a new factory in Hull. From 1954, Imperial portable typewriters would be manufactured at the Hull factory while the original Leicester works would make the Imperial 66. This individual model 66 was used by the University of Swansea Department of Mathematics and had interchangable keyboards and typebaskets for mathematic Greek and English keyboards.

By the late 1960s, Imperial succumbed to cheaper overseas production costs and began to import machines from Japan. In the 1970s, Imperial was taken over by US electronics giant Litton Industries, which also swallowed up Royal Typewriters, and after a brief revival, the Imperial name disappeared completely.