(1) Any aircraft held by a dealer listed and used as provided in section 360.63, except that aircraft held by dealers on October 1, of each year, shall be registered and the entire tax provided by sections 360.511 to 360.67 shall be paid for the portion of the fiscal year, prorated on a monthly basis remaining after the aircraft came into the possession of the dealer. It is further provided that a dealer who has previously had aircraft on withholding may register such aircraft in September of each fiscal year by payment of an amount equal to one-third of the annual tax, which tax shall be applicable for the months of September through December and in January the dealer may again list these aircraft on the dealer's withholding form.
(2) Aircraft remaining in the possession of aircraft manufacturers ten months after completion shall become subject to the tax provided by sections 360.511 to 360.67. The tax shall be computed from the expiration of the ten months period and shall be prorated on a monthly basis.
(3) Aircraft while in the hands of aircraft refitters for the purpose of being refitted or modified or both, and while being refitted or modified or both.
(4) Aircraft licensed under section 144E.12 and used exclusively to provide air ambulance service.