Dropping of "was" from "A couple of ministers had to resign too, among them [was] Interior Minister Fouchet."

Solution 1:

There is a parenthetical involved here, and the internal grammar of parentheticals is often far more relaxed than within sentences proper.

[Several] ministers had to resign too, among them Interior Minister Fouchet.

A more logical ordering, clearly showing the parenthetical (subclass additional non-essential information) is:

[Several] ministers, among them Interior Minister Fouchet, had to resign too.

The length of the parenthetical is no doubt the reason why it is considered acceptable to postpose it: 'among them Bob Todd' would be less amenable to postposition. It appears illogical, but is acceptable.