Domestic Use of PC2 in 1891 -- a homely gem!

The first six-centime Arms postal card was issued in a quantity of only 3,000  on June 16, 1874, to pay the 6c German treaty rate.  Used examples are scarce, the entire printing having sold out in only two months.  It's so scarce in fact that in 50 years of collecting, I had only acquired two used examples until the remarkable card shown below surfaced in a bourse dealer's acquisitions.  And I don't recall seeing a used PC2 in the François Kaufmann collection when it was exhibited at Finland's FIP postal stationery exhibition in the 1980s.

Here we see this homely gem, printed locally by Pierre Bruck with a basic printing press, used domestically nearly 17 years after issuance.  This was well into the period when Luxembourgers were using the high-quality Allegory postal cards printed in Holland in large quantities by Enschedé using then state-of-the-art printing technology.

The three double-circle cancels show the card postmarked at Clervaux 1:00-2:00 p.m. on Friday, February 27, 1891, received in transit at Diekirch 7:00-8:00 p.m. the same day, reaching its destination of Vianden at 9:00-10:00 a.m. the next day. 

Some of my philatelic friends in Luxembourg opine that out-of-period uses of the postal stationery were the work of collectors.  This and others in my collection suggest that that was often not the case.  The frugal Luxembourgers of this era weren't about to waste six centimes when an old forgotten card turned up.  By 1891, the German treaty rate was ten not six centimes, but the domestic postal card rate remained at 5 centimes and the first-issue cards were still valid (they weren't demonitized until December 31, 1905).  So the writer lost only one centime when he used this 6c card to send his message across the Luxembourg Ardennes from Clervaux to Vianden!