This is the shop manual that Bitter dealers used. It is actually the Opel Monza/Senator manual.

This means that for example the body repair section exclusively refers to the respective Opels and is quite useless for the Bitter owner, but the mechanical sections of the manual do apply to the Bitter as they do for the Monza/Senator.

There might be the other odd piece of information that applies to the Opels only, but the manual is an extremely valuable resource to keep your Bitter in shape.