Except as provided in § 12–208 of this subtitle, each pre–existing authority continues to exist. Except as provided in paragraph (3) of this subsection, a pre-existing authority governed only by this title: may exercise the powers granted by Subtitles 6 and 7 and §§ 12-501, 12-502, 12-504, and 12-506(a) of this title; and if it adopts articles of organization, may exercise the powers listed in § 12-503 of this title that are authorized by the articles of organization in accordance with § 12-205(b)(1)(vi) of this subtitle; and is entitled to the exemptions from State law provided in § 12-505 of this title. Except as provided in paragraph (3) of this subsection, a pre-existing authority governed by this title and by a title in this Division II that is applicable in a particular political subdivision: may exercise the powers granted under the title that applies to the particular political subdivision; may exercise the powers granted by Subtitles 6 and 7 and §§ 12-501, 12-502, 12-504, and 12-506(a) of this title as modified by the title that applies to the particular political subdivision; if it adopts articles of organization, may exercise the powers listed in § 12-503 of this title that are authorized by the articles of organization in accordance with § 12-205(b)(1)(vi) of this subtitle; and is entitled to the exemptions from State law provided in § 12-505 of this title. If articles of organization are adopted, the powers set forth in §§ 12-501 through 12-506(a) of this title may be limited to the extent allowed under §§ 12-205(b)(2) and 12-207 of this subtitle.