(a) General rule.--In addition to the restrictions made by other provisions of this part in particular cases or by any other provision of law, no city shall exercise the right of eminent domain against:
(1) Land now occupied by any building which was used during the Colonial or Revolutionary period as a place of assembly by the Council of the Colony of Pennsylvania, the Supreme Executive Council of the Commonwealth of Pennsylvania or the Congress of the United States.
(2) Land occupied by any fort, redoubt or blockhouse erected during the Colonial or Revolutionary period or any building used as headquarters by the Commander-in-Chief of the Continental Army.
(3) The site of any building, fort, redoubt, blockhouse or headquarters, which are preserved for their historic associations and not for private profit.
(b) Colonial and Revolutionary period.--The Colonial and Revolutionary period shall be deemed to have ended on September 3, 1783.