North Borneo 1939 postage due used and "Fu Kan Shi" official seals

A very expensive set if genuine. I have been informed that the 2c is suspicious and I am not certain the rest are authentic postmarks. The 4c has a nice registration cancellation. The 8c and 10c postmarks are too similar for my liking. This is the danger of buying rare used NB.
I have included a scan of  Japanese Occupation "officially sealed" labels for priority mail with a japanese overprint on this postage due issue that excluded the 10c stamp. The japanese characters  "Fu Kan Shi" can be translated as "paper seal" both in japanese and chinese. They were originally thought to be used for sealing official secret letters. Any unauthorised opening of such letters would have resulted in death as punishment. Quite a believable hypothesis considering how cruel and savage the occupational forces were. This was not true as civilian letters were also found with these seals. They were used to seal special mail such as registered letters containing valuables like cash or postage stamps usually at the flaps of the envelope. However, none of the 4 stamps shown above were ever found "used" on envelopes apart from the NB war tax 1c stamp with similar overprint. The evidence was mainly based on similarly overprinted stamps of Sarawak.
As they are not valid for use as postage stamps, they tend not to be listed. Still they are quite collectable. I bought them for a few dollars in Sandakan in my youth. I gather they might be valuable.

my favourite North Borneo stamps

Just love the detail and the colour. Part of the 1911 high values set. The middle $5 has an unlisted lighter brighter shade more similar to the shade on the 1925 set. Could it have been a colour trial?
The $10 stamp on the extreme right is actually from the 1925 set and is perf 12 rather 14. I do not possess a 1911 $10 stamp as yet.

Paquebot postmarks

I always have a soft spot for paquebots. Paquebot pronounced "pakbo" is a french term for packet-boat. In the 16th century, state letters and despatches were referred to as "packet". Paquebot were essentially mail carrying boats. Later on it was used to describe postal marking which is used for letters mailed at sea for processing at the next port of call. This is often in another country such that the stamps used were not indigenous. Here we have examples of NB stamps processed at Singapore. Paquebot cancellations came into use in 1894. The real Paquebot era happened in the first half of the twentieth century. With the growing popularity of air mail and air travel, ship mail slowly declined.
The rectangular types shown is surprisingly not listed in Ted Proud's book. It is similar to the ones used in Sandakan except the letters are taller. They are probably common as there are 2 examples above as well as 2 more with HK postmarks below.
The 3c railway stamp has a Singapore transit date stamp.
Update This rectangular paquebot franking is probably of HK origin rather than NB.

Here we have paquebots marks and arrival date stamps for Hong Kong.

Paquebot mark that was used in Jesselton around 1936. 5c MBE 1922 with part of a KUCHING cancel. Initially I thought it was HK. Use of the stamp in neighbouring Sarawak would make more sense. Incidentally, Sarawak did not have an issue of stamps overprinted with MBE 1922.

Update Added a dubious looking Hong Kong cancel on a good NB stamp.

Update Added a really nice Singapore paquebot.

A nice Hong Kong cancellation.

interesting postmarks

Arrival postmarks for overseas mail, UK etc.

North Borneo Train Mail

The 5 bar mark is quite rare, I think. According to SG, it was used for railway mail during 1945/55 and also as a paquebot at Jesselton around 1950. Others has suggested that this was a cancellation used on the stretch of railway between Beaufort and Jesselton in 1948. Proud also mentioned that it was used for "loose mail", late letters etc.
Update I have recently seen a clear strike of this 5 bar within an oval cancellation on a 5c 1964 NB overprinted Sabah stamp which throws the above dates into dispute.

The "TRAIN MAIL" postmarks are relatively common and were in use from 1932 until 1942 when the railway was extensively damaged in the war.
The "TRAIN P O" postmark on the 1c tapir was in use between 1916 and 1923 is more difficult to find. It comes in 2 sizes, the earlier version being slightly smaller.
There are 9 or more different railway date stamps known for North Borneo. They were variously in use between 1916 and late 1970s.
Update Added stamp with a nice clean strike of  "TRAIN MAIL" on 2c Travellers' Palm.
Update Added the 3c railway green with a "MAIL TRAIN"  single ring postmark. This was used in 1920s to early 1930s. They are not common.
Update Added the 3c Murut with the larger version of  "MAIL TRAIN" postmark. They must be less uncommon than I thought.

"MAIL TRAIN" cancel, this time in blue.

"TRAIN P O" cancel again in blue.

"TRAIN P O" in black. I thought it was a GPO at first glance.

"MAIL TRAIN"

Another "MAIL TRAIN"