all, and, (b) where the whole of such property is sold to diffe r ent buyers, the buye of the lot o f greatest value is entitled to s uch documents. But in case (a) the s eller, and in case (b) the buyer, o f the lot of greatest value, is bound, upon every reasonable request by the buyer, or by any of the other b uyers, as the case may be, and at the cost of the person making the request, to produce the said docum e nts and furnish such true copies t h ereof or extracts therefrom as he m ay require; and in the meantime, the seller, or the buyer of the l o t of greatest value, as the case m a y be, shall keep the said docum e nts safe, uncancelled and undefac e d, unless prevented from so doin g by fire or other inevitable acciden t .