Vauxhall Cavalier Mk1 - Haynes Owners Workshop Manual

Interestingly this Haynes manual is specified for the Vauxhall Cavalier Mk1, of course I am sure you will know that this version of the Cavalier Coupe is a rebranded Opel Manta B series and the Cavalier Saloon is the same as the Opel Ascona B series. There are minor trim issues between the 2 GM brands but they are underpinned by the same frame and mechanical parts.
Covering the period from 1975 to 1977, there won't be any information relating to the later face lifted Opels with their plastic trim sections, fuel injection and 5 speed gearboxes.

Vauxhall Cavalier Mk1 - Opel Manta in disguise