Hi,
I'm assuming your husband did his C&G before he started work? I think that's all they will want from him is his C&G certificate. If, however, he completed an apprenticeship while studying, then his study record will be required. This would come in the form of an employers/tutors record of the stages of acheivement obtained during the apprenticeship.

If he didnt do an apprenticeship, then you should contact NZIS on the phone and get an immediate answer. Its not worth taking risks on speculative information when it comes to your ITA!!