(2) Where in a case within subsection (1) a tangible bill of lading has been issued in a set of parts, unless otherwise agreed if the documents are not to be sent from abroad the buyer may demand tender of the full set; otherwise only one part of the bill of lading need be tendered. Even if the agreement expressly requires a full set:
(a) Due tender of a single part is acceptable within the provisions of this article on cure of improper delivery (subsection (1) of section 2-508); and
(b) Even though the full set is demanded, if the documents are sent from abroad the person tendering an incomplete set may nevertheless require payment upon furnishing an indemnity which the buyer in good faith deems adequate.
(3) A shipment by water or by air or a contract contemplating such shipment is "overseas" insofar as by usage of trade or agreement it is subject to the commercial, financing or shipping practices characteristic of international deep water commerce.