1926 Red Overprint, 1c-20c five different, also Black overprint $5 red, yellow & gray, all used, last five canceled by KOBDO MONGOLIA datestamps on pieces, fine-v.f. (Cat No. 16b-20b,23a) (Image)

Est.US$1,000

1926 20c yellow brown, black overprint, 50c brown and olive green, black and violet overprints, three used singles, fine-v.f., with handstamp guarantees, cat. $635 (Cat No. 20a,21-21a) (Image)

Cat. $635, Est.US$300

1926 50c brown and olive green, $1 brown and salmon, violet overprints, l.h., fine, with handstamp guarantees, cat. $850 (Cat No. 21-22) (Image)

Cat. $850, Est.US$350

1926 50c brown and olive green, $1 brown and salmon, violet overprints, used, fine, with handstamp guarantees, cat. $735 (Cat No. 21-22) (Image)

Cat. $735, Est.US$300

1926 $1 brown and salmon, violet overprint, h.r., v.f., with handstamp guarantee, cat. $550 (Cat No. 22) (Image)

Cat. $550, Est.US$300

1927 native cover franked on back with 2x25c green, tied by Ulan Bator cds and addressed to Manchuria, with Kalgan arrival alongside, additional markings of Manchuli on front, fine and unusual cover without the customary Chinese postage added on arrival (Image)

Est.US$250

1928 (20 June) part of registered cover franked with 5m and 20m (defective) paying foreign rate from Ulan Bator to Harbin, with boxed "Pay postage due in stamps" and "18" in manuscript, with pair of 5c Chinese postage dues added and tied by Harbin (2 July) pmk (Image)

Est.US$500

1931 (7 Jan) red-band cover from Ulan Bator to Kalgan, franked on back with single 40c lemon & black, departure cds repeated on front, without any additional Chinese markings or franking (Cat No. 40) (Image)

Est.US$250