The new cars for the lower and upper medium segments were to share a platform, with various trim and styling differences to distinguish the two different models. The two models would in effect replace four existing vehicles in the British Leyland range – the Maestro would simultaneously replace both the Austin Allegro and Maxi, whilst the Montego replaced the Austin Ambassador and Morris Ital, these latter two having been recent facelifts of the Princess and Morris Marina. Since all but the Allegro were made at the Cowley plant, this rationalization would give the cost benefits of production automation and flexibility. This common platform was given the project name LC10, using the Leyland Cars project sequence (LC8 became the Austin Mini Metro on its launch in 1980, LC9 became the Triumph Acclaim when it was launched in 1981). Preliminary design work for LC10 began in 1977, with production scheduled to begin around 1980 – which would have seen it go on sale around the same time as the Ford Escort MK3 and the original Vauxhall Astra.