Where a light railway order authorising the construction of a light railway on public roads empowers any local authority to acquire the railway, and an application is made under the principal Act by any local or road authorities in whose area any part of the railway is situate for an order amending the original order, the amending order may, notwithstanding anything in proviso (c) of section twenty-four of the principal Act, determine or vary the authorities by whom the railway may be acquired, and may provide for the maintenance, management, and working of the railway when acquired under the order, and may make such further provisions as are necessary for giving full effect to the order :

Provided that the provisions of the original order relating to the period within which the right of acquiring the railway must be exercised, and to the basis on which the purchase money is to be assessed, shall not be altered by the amending order without the consent of the owners of the railway.