A £1 brown-lilac IR Official stamp issued between 1884 and 1888 will auction Spink London on April 14 with a £35,000 ($58,611) estimate.
The lot will provide the highlight of the hotly anticipated Drs. Joanne and Edward Dauer Collection of Great Britain sale.
Few brown-lilacs have survived due to the use of fugitive inks, which wash away under water and were designed to prevent recipients removing the stamps through soaking.
This unused example was set aside for internal mailing by the Inland Revenue and features the desirable "IR OFFICIAL" overprint.
It retains a large portion of the original gum and is offered in very fine condition.
An 1883-1884 cobalt blue 10 shilling with part of its original gum is valued at £20,000 ($33,492).
It's exceptionally well centred with a superb impression and is one of very few examples available in this particular shade.
A £1 dull blue-green IR Official from 1902-1904 is another highlight, marred only by some minor hinge marks at the top.
It carries an identical estimate of £20,000 ($33,492).
In January a 1927 Newfoundland 60c black "Air Mail/De Pinedo/1927" overprint made $45,000 at the auction of the Dauer's North American and Canadian collection at Spink New York.
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