It took me a bit of time to work it out. Seeing whole examples on Cassels' covers helped a lot. The partial franking on the 1c stamp has an "E" on its upper end and a small cross at the other end. There are some letters in between but it is too smudgy to decipher the word. It has a date with month followed by day on the same line with the year below it which is unlike the Labuan postmarks of similar design. It is a Singapore transit date stamp.
The franking on the 4c is probably a "straits" period Labuan postmark but can be Singapore. The postmark has the same thick bar as Singapore but one can see above the year is part of the number "24" probably followed by the month on the same line. Possibly a Labuan D10 postmark on the Proud classification.
Another straits type franking but larger. It is most probably a Singapore transit date stamp.
Yet another straits type cancel with the thick bar within a double ring. There are letters to suggest "sungei". It is possible that it may be an arrival postmark for a place in Malaya. But with the letters AP in the second postmark, I think this is again a Singapore date stamp with an error of a "U" instead of an "I". But Sungei Pettani etc is still a possibility.
1886 stamp and the thick curved bar straits type at the extreme right bottom corner is likely to be a very small part of a Singapore transit marking.
A clear Singapore straits type cancellation. Note the small Maltese Cross left lower corner which adds a nice touch to the design.