The elusive Mempakul 7 bar cancellation (1897-1898). The stamp on the left has 2 and a bit thick bars with the right dimensions. Interestingly, this stamp has a faint blue postmark, possibly a transit marking. The stamp on the right has a 9 bar Labuan cancellation which often gets mistaken for a Mempakul. NB stamps were used in Labuan especially between 1890 and 1907 when it was administered by the British North Borneo Company.
Update Looking more closely, the blue transit postmark has a year of 1894 and is probably the blue postmark D2 of Kudat. That means the bar cancel of Mempakul dated earlier from what it says in Proud's book. I think this is a case of "double happiness" with 2 rare cancels on one stamp!
Update I have taken note of Gantian's comment. Hopefully, I can clarify this in a later posting.