Why do you think that ordinance governs?
That ordinance defined "inoperable motor vehicle," not "in operating condition" - and the first definition provided for an "inoperable motor vehicle" is one that "is not in operating condition".
If you believe the second portion of the ordinance governs your landlord's right to tow, I would read "on which there are displayed neither valid license plates nor a valid inspection decal" independently of "which for a period of 60 days or longer", such that your vehicle is inoperable if it has "neither valid license plates nor a valid inspection decal" from the moment that occurs. However if you had valid plates it cannot be said that your vehicle "neither valid license plates nor a valid inspection decal". You had one but not the other.

