I recently came across to this nice stamp in ebay, bearing a supposedly rare postmark. The first thing that you'll notice is the oval of bars postmark at the top right corner, which means that the stamp is originally cancelled-to-ordered.
I don't know the exact date but it is likely to be Oct 192_. This date is problematic because the stamp is released on the 1st of July 1909 and overprinted with "20 cents" on the 7th of September 1909 (only after 2 months of its release). The town is probably Kuching because the third letter resembles C more than D. However, because Kuching is a 7 letter word, while Kudat is a 5 letter word, the K would be much lower in the circle if it was Kuching.
There is a similar stamp here (Silamstar's). Compare the postmark, particularly the town and date.