The editor had received the pair from a Mr. Perez who was then in London. This mention reported in the April 1881 issue of the fitly magazine Le Timbre Poste published by J.B. Moens. He stated, "It (the stamp) should serve, they tell us, for house delivery of letters which a private enterprise has taken on". He also reported he had seen an imperforate example of the stamp printed in black which he had been told was an essay (proof?). Moens again mentioned the stamps in the May 1882 issue of his magazine.
He stated the journal Gruia del Collecionista de Sellos de Correos (published in Valparaiso, Chile) had received a communication from a correspondent living in Barranquilla (Colombia) stating the service had been set up by Octavio A. S. Mora, which explained the monogram OASM appearing on the stamps.
Apparently, at that time these private stamps were not in use, as the main part of the order had not been received from the Paris printer.
The service operated by Mora would collect letters from the Barranquilla post office, affix one of the private stamps and deliver them to the addressees on payment of the delivery charge.
He also intended to set up mail boxes in several localities of the country where letters bearing his stamps would be delivered to the Barranquilla post office. Two such localities were Sabanalarga and Puerto Colombia. It has long been believed this private delivery service was not put into operation. However, the recent discovery of an apparently postally cancelled example of the brown stamp, (Fig. 2), indicates this to be wrong.