Nothing in this chapter shall be construed as impairing the legality or organization of any fire protection district heretofore organized pursuant to law, nor the legality of any act of such district done in accordance with the prior law, nor shall it be deemed to affect the legality of the election of any officer of any such existing fire protection district, and all directors and officers duly elected, qualified and holding office at the time of the taking effect of this chapter shall continue to serve in such office until the expiration of their present terms; provided, however, that such fire protection districts as have existed heretofore shall comply with the provisions of this chapter as soon as they can conveniently do so and thereafter be governed by the provisions of this chapter. Nor shall anything in this chapter be deemed in any way to affect the existing indebtedness of any fire protection district created under and by virtue of the provisions of chapter 30, title 30, Idaho Code. All such existing fire protection districts, and the lawful acts of their officers and agents, are hereby declared prima facie lawful as de facto fire protection districts; provided, however, that such districts shall comply with the provisions of this chapter as soon as they can conveniently do so and thereafter be governed by the provisions of this chapter.