If, however, after having served notice to Buyers as above, Sellers fail to make shipment within such 8 days, then the contract shall be deemed to have called for shipment during the originally stipulated period plus 8 days, at contract price less 1.50%, and any settlement for default shall be calculated on that basis. If any allowance becomes due under this clause, the contract price shall be deemed to be the original contract price less the allowance and any other contractual differences shall be settled on the basis of such reduced price.