I have to respectfully disagree.. during my time in Kandahar in 2009/2010 I saw alot of stuff in the market with serif stamps - fake WW1-dated British surveying instruments being an espescially popular item. I think Afghan fakery has evolved alot over the last 10 years or so as they start dealing with a more and more educated consumer base.Look at the Type Font of the "1887" and you will see it is "serifed" style; THis style fell out of use Before WW II, because it was difficult to generate the stamps, and they were subject to fractures of the serifs ( "tails") on letters and Numbers.
SO, the Marking was NOT a "fraud" to help US soldiers import it from Ganistan...more likely a Rack number or store number for internal inventory of some small user. The chances of Serifed stamps existing in good condition in either Iraq or Afghanistan is like winning the El Gordo Lottery in Spain.
Interesting question, now..which user?
Not that that stopped a certain young Captain from battlegroup headquarters from buying about $2000 worth of ``diamonds`` at the KAF market...