The stamps were bought recently from our society auction. Labuan prewar photos are really not that common. These were supposed to be taken in 1935, probably by an expatriate.
The Labuan K1 was recorded as used between 1864 and 1882. The very earliest ones were in black as shown by a famous front piece with the cancellations on Hong Kong stamps. Then they were mostly in red like this one and then the ink used was changed back to black as the red ink was not very clear. I have another 2 in red which is much better than this one and would be shown at a later date.
The interesting thing about K1 was that it was in use for 15 years before the first adhesives for Labuan appeared in 1879. During that time, it was used on Indian, Straits, Hong Kong and possibly Ceylon stamps. But examples so far are very rare. So happy hunting!
This is shown because it has a Labuan D9 transit cancellation. The Brunei temporary cancel D6 shown here is one of the rarest of Brunei postmarks and was used for a year between Feb 1927 and Jan 1928. So far no cover is recorded but I do have it on a large piece.