During the first flashback scene where Celia Norris is cycling on the road, she goes by two Austin Maxis. That bit was set in 1965. The Austin Maxi was launched in 1969.
In the scene on the train, there are several football fans wearing rosettes, but these had gone out of fashion long before 1980, when the film was made. Additionally, the scarves that the fans wear are of a type that. like rosettes, were not in fashion in 1980.