Definitely non-classified.
The rules of the system say something like: if you've had a classification in one year then failed to attain a classification in the following year, you are 'non-classified'. This is distinct from 'unclassified' which is reserved for people who have never attained a classification.
Your situation is complicated a bit, as you've never held a classification under the current system. The 1st class you used to hold was a stronger classification than the current first class (it overlapped with the current 'Bowman' class, which didn't then exist). But I'd still go with 'N/C'.