I will have to leave the decision as to whether these are the real stuff entirely in the hands of readers. I will also welcome any opinion or advice. It would be rare to have complete sheets of 50 like these. They are rather fragile and large which makes storage and displaying a bit of a problem.
I had to put them in glass frames when I showed them to members of the Sarawak Society at last year's AGM weekend. No individual could expressed a definite opinion even though there was one who was not satisfied with the shade of the ink. But these were ordinary office ink pads where were used originally in the overprinting.
Each overprint was applied individually. One has to admire the precision even though there were minor individual differences in the inking, position and slant of the overprints.
I read somewhere that they were carried out by a group of soldiers or clerks under the strict supervision of a superior officer and would have been physically punished if they dare to make a mistake. Then there was an article that mentioned a particular local postal clerk was responsible.
It was possibly a mixture of these scenarios as the Brunei overprints were said to have been carried out on two separate instances. They were first overprinted in or just before September 1942 as they were first put on sale that month.
Then when the 3 line overprints came out for North Borneo in October 1944, the Brunei were again overprinted but surprisingly with the same 1 line overprint. However, it is also maintained by some that the overprints were made as and to when they were needed between and including these two dates.