A savings bank is authorized to invest in operating subsidiaries, the activities of which are exclusively limited to activities which could be conducted directly by the parent savings bank. Because an operating subsidiary is limited to activities that could otherwise be conducted directly by the savings bank, operating subsidiary investment is not limited by the percentage of assets or dollar amount restrictions applicable to subsidiary corporations as set forth in §75.325 of this title (relating to Subsidiary Investment and Debt Limitation). Notwithstanding this exclusion, all other provisions of this chapter applicable to a subsidiary apply equally to an operating subsidiary.