Our 7 was manufactured in the Norwich factory where Elises are done nowadays. However, many (most?) Sevens were produced in the Cheshunt factory in the Great London Area. A visit September 2008 confirmed that the old Lotus buildings are still there. The Lotus main buliding is now a plastics factory and the building where Lotus Components resided is now a fitness center. The buildings as such seem unaltered, even the winch where they lowered the Sevens from the first floor remains, as does the ramp of the Lotus factory (see photos).
Cheshunt factory 2008
Lotus Components (now gym) 2008
Lotus Components ca. 1962
Ramp 2008