Jesselton paquebot postcard

A philatelic plain postcard posted on board the good ship Kimanis on its way to Jesselton probably from Singapore ? via Labuan. It has a Jesselton postmark of 25 AU 55 which would have been applied at the local post office on arrival and then forwarded to the address in USA. The paquebot marking was the Jesselton SL6 with a value of x 20.
However, there are some inconsistencies with this card. The prevailing rate for a postcard to USA by airmail was 60c and ordinary mail was probably 12c. We have a total of 30c + 2d. Looks like it was overpaid for ordinary mail and the 2d GB stamp was superfluous but got cancelled anyway. By UPU rules, the GB stamp would not have been valid. I presume the Kimanis was registered at Singapore. Singapore stamps could have been used in international waters and NB stamps within the territorial seas of North Borneo. Some of these regulations were difficult to understand and the rules were not strictly adhered to by postal clerks.
The likely scenario was that a passenger on the Kimanis nearing Jesselton decided to post his pre prepared postcard with the GB stamp. He was advised that it was invalid and that he would have to use NB stamps. It was over franked as nobody knew the prevailing rate to USA.
There are disappointingly no arrival or transit markings which might also suggest this is entirely a CTO item. I once bid unsuccessfully for a NB paquebot cover bearing a stamp from India. One wonders how that was possible unless the sea going vessel was flying the Indian flag which would have been highly unlikely. Or was it a case of when in the high seas, anything goes!
Moreover, by convention, the adhesives on a paquebot cover should have been cancelled by a cds and the paquebot marking applied elsewhere. This was later simplified by the introduction of the "paquebot cds", an example of which you can see by clicking here.

The MV (maritime vessel?) Kimanis was built by the Caledon Company at Dundee, Scotland in 1951. There was also a record of a ship with the same name serving North Borneo in the late 19th century.
Kimanis was one of the ships of the Straits Steamship Company that plied the route between Singapore and North Borneo going as far as Tawau. It is a name which is well remembered by the locals with some affection. As a child, I used to fish with friends at the docks around the early 1970s. It was one the names that I can recall. We also had relatives in Lahad Datu who visited regularly travelling on these vessels. The situation was so safe and relaxed in those happy days that it was possible to wander aboard  to look around. I once got lost and almost panicked in case it was leaving dock.

The dock area behind Sandakan central bus station on Jalan Satu. It all looks very different nowadays and there is no such view as the sea was reclaimed and built on.