All three volumes are well worth picking up from ‘Amazon.Germany’. The picture quality is very good, indeed.
As for the film title…yes, it’s a bit of a handful, so it’s just as easy to call it ‘Amigos’. This appears to be the title for it on the front of ‘Italowestern - Enzyklopädie No. 1’. Bearing in mind the relationship between Giuliano Gemma and Mario Adorf, I think it’s a more appropriate title.