In all cases in which any property required to be included in the gross estate or total amount of the generation-skipping transfer referred to in section 77-2108 does not come into possession of the personal representative, executor, or administrator as such, he or she shall, in the case of a trust involving temporary interests described in such section, be entitled to recover from the fiduciary in possession of the corpus of such trust, and in all other cases from the persons interested in the estate or transfer, the proportionate amount of such tax payable by such fiduciary or persons with which they are chargeable under such section.