Section 13-907 - Transfer of registration within certain classes(a) At any time during a registration year, the owner of a vehicle registered in one of the classes listed in subsection (b) of this section may apply to the Administration for a transfer of the registration for that vehicle to any other permissible registration that is in the same class and has a higher registration fee, whether the transfer is for the same vehicle or is to another vehicle owned by the same person.(b) A transfer of registration under this section may be made only within the following classes: (2) Class F (tractors); and(c)(1) For a new registration under this section, the registration fee is as provided in this subsection.(2) If the new registration is issued on or before the last day of the sixth month of the registration year for that class of vehicle, the registration fee is the full registration fee ordinarily required for the new registration, with a credit for the other fee already paid.(3) If the new registration is issued on or after the first day of the seventh month of the registration year for that class of vehicle, the registration fee is one half of the registration fee ordinarily required for the new registration, with a credit for so much of the other fee already paid as is allocable to the last six months of the registration year.