Ben, your example as proof is, itself, flawed. You are correct that you wouldn't - or at least shouldn't - write "the French, the Italians, Spanish and Portuguese." The problem, however, isn't the lack of "the" preceeding Spanish or Portuguese, it's the one dangling afore the Italians. You could quite happily write "the French, Italians, Spanish and Portuguese." It's all about balancing what each word is associated with. In my valid option, the word "the" applies to each item in the list, so doesn't need to be repeated.
I’m going to sew dissent and disagree here. Including the second ‘was’ might be strictly correct, but in example A it is inferred. No one’s in danger of misunderstanding the sentence where it is missing, so you are fine to leave it out.
Thanks Kate, I've since had a reply from a grammar site I checked and they said similar. B is 'correct', but more formal, and A is acceptable. In the context of the paragraph, I think I can get away with A after all!