These cards were rated at 1d rather than 1/2d as technically, with the extra printing, they were classed as 'letter cards'.
Although it was expected that these special cards would be used, or at least favor canceled, many were taken away just as sold. The above is such an untouched 'mint' copy.
Above the postage the receipts went to the Rowland Hill Memorial Fund. As an estimated 20,000 persons attended on the opening night of the 16th, these special cards were quickly sold out. When the announcement was made about 10 PM, a run immediately took place on 'ordinary' postcards.
In 1985, Mr. H. Dagnall published his book concerning the "British Stamped Postcards & Letter Cards". In it he included a quotation from the 9th June 1890 letter sent from the Inland Revenue to the Treasury concerning the production of the Jubilee Post Card.
" ... we received a further request from the Postmaster-General for the loan of four electros of the one penny post card stamp to be used in the printing of a Jubilee Memorial Post card of one penny, to be manufactured by Messrs De La Rue & Company under the supervision of our Officers at their Factory in Bunhill Row. We agreed to this and 10,000 of these cards were ordered and manufactured and in the course of the exhibition a further 1500 were produced at the request of the Post Office Authorities."
No mention of the additional cards is made in the 27th May, 1890 "Report Of The Controller", Mr. R. C. Tombs. From this letter, the total of the special Jubilee Guildhall Post Cards would raise to 11,500. The additional production order should have been given out on Saturday morning, 17th May, printed that day and then delivered for sale on Monday. This might explain the larger than expected number of cards seen with a cancel date of the 19th May 1890 !
John Davies has kindly sent me a scan of the De La Rue accounting, showing that 11,980 cards were printed from the two orders and delivered to the Post Office for the Guildhall Celebration. Thus the G.P.O.'s re-order for 1,500 was actually delivered as 1,980 cards.
When it appeared that the stock on hand of the 'ordinary' cards would also be quickly depleted, a call went out to all the branch post-offices in the neighborhood. Further supplies of both current types were requisitioned for Guildhall use. In all, 19,300 'inland' cards and 1,208 of the 'foreign service' type were sold.
When these too were exhausted, a demand set in for embossed envelopes and registered letter envelopes. Of these, 452 were sold and canceled. No differentiation of the types was made in the 'Report' of Mr. R. C. Tombs.
Some enterprising attendees used stamps 'from the past', including the Penny Black, to receive the special Guildhall Jubilee cancel. One item, on an unaddressed Inland Revenue envelope, used an Imprimatur "AK" from Plate 41, Die II.