In addition, for the purposes of sections 452, 459, 460, 461 and 463, the expression “election expense” includes expenses referred to in paragraph 9 of section 453 and the expression “official agent” includes a private intervenor within the meaning of Division VIII.1 if the private intervenor is an elector, and the representative of such an intervenor if the private intervenor is a group of electors.