A £1 brown-lilac IR Official stamp, issued between 1884-1888, has sold for £45,000 ($75,217) at Spink's sale of the Dauer Collection of Great Britain.
The auction took place on April 14 in London, with the lot achieving an increase of 28.5% on an estimate of £35,000 ($58,611).
Relatively few of the brown-lilac stamps are available in good condition because they were printed using fugitive inks, which wash off when exposed to water to discourage reuse.
The example sold was set aside for use by the Inland Revenue and features the characteristic "IR OFFICIAL" overprint.
It also retains a large portion of its original gum, increasing its desirability among collectors.
A 1902-1904 £1 dull blue-green IR Official also sold well, achieving £20,000 ($33,430).
It displays a strong impression and bold colouring, marred only by some minor hinge marks along the top edge.
Another high performing lot was a 1883-1884 cobalt blue 10 shilling which made £20,000 ($33,430).
It features an exceptionally well-centred impression with large, even margins and is one of only a small number available in this shade.
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