"Good" should be accepted together with "nice" (shouldn't it? Reported)
If we did not have = Tusingekuwa na
If we had not had = Tusingalikuwa na
I agree. 'if we did not have' is the negative conditional PRESENT, and is thus an incorrect translation, IMHO.
The negative conditional PAST TENSE would be 'if we had not had . . . ', or 'if we'd not had . . .'