A questionable 14c Winter Letter Rate combination cover from Tientsin

This is a 8 February 1898 letter from the Lt. Dundas correspondence from Tientsin to London. As the letter was posted in during the winter months it travelled overland due to the frozen sea route thus the special Winter Rate of 14c applied. The postage was paid by 4c and 10c ICP issue which were canceled by a Tientsin Pa-kua (6-barred device for obliterating stamps) and the dollar "chop" struck next to them. The letter arrived in Shanghai on 14 February, six days in transit and a Hong Kong QV 10c (overseas postage) was applied by the Shanghai British Post Office since China was not a member of the U.P.U. at that time. The letter was sent to Hong Kong then by British Packet to England.

However, there is a problem, the Pa-kua tying the stamps appears to be in BLACK but the Tiensin dater is in reddish-brown!

A member of ours has two covers from the same correspondence dated 14 January 1898 and 3 March 1898 at Tientsin says that both covers have stamps missing. The 14 January 1898 is shown below:-

Since this letter is dated two weeks before the subject cover, the 14c rate should apply and we believe that a 10c stamp is missing at the top right corner. The main point is, look at the colour of the Tientsin Pa-kua, it is of the same shade of reddish-brown as the the Tientsin dater. Hence we believe that either the clerk at Tientsin used two ink pads for cancellation or someone added two stamps subsequently and cancelled them with a fake Tientsin Pa-kua. Unfortuantely, it is impossible to see whether the stamps were added through the low resolution scans but the owner of the cover should have it expertised by a reputable expert.

Enlarged scans of both covers