Some things I find interesting.
 Hope you also do....

Disabled American Veterans (DAV) Used Covers

DAV is very guarded with the covers returned with contributions: Perhaps extremely protective of its contributors, DAV does NOT make "used" covers available to collectors.

However, DAV covers showing postal usage are available to collectors albeit not with their intended usage. 

Recipients of DAV solicitations sometimes use these franked return covers to send other letters.  The DAV address is crossed out or written over and a new address is added.  Such covers are eventually delivered to the new addressee but they first take an unintended detour. 

Because the covers are preprinted with the bar code of the DAV, USPS automatic sorting equipment reads that the covers should go to the DAV and so they do.   Along with thousands of similar covers containing contributions, these non-DAV intended covers are opened "accidentally" before it is discovered that they are addressed to other recipients.  Notice the neither cover has the Facing Identification Marks (FIMs) now required by USPS to receive the highest discounts for presorting outgoing mail.

The opened envelopes are sealed at the bottom with transparent tape and the message "OPENED BY MISTAKE BY D. A. V."  is added before being reentered into the mail stream. 

My earliest example is a 1992 cover sent from Westchester NY and addressed to LINN'S in Sidney OH. 
This cover is franked with five untagged Circus Wagon stamps (KRAUSE-MINKUS 931z, SCOTT 2452a) plus two block tagged Locomotive stamps (SCOTT 2226, KRAUSE-MINKUS 873)

A second example was mailed in 1994 in Royal Oak MI and is addressed to a person in the same USPS sectional center.   Rather than being delivered as essentially local mail, the cover first made a trip to Cincinnati OH. 

Of special interest to collectors of USPS spray cancels is the unusual repeating "CINCINNATI" spray which also ties the 5¢ stamps to the cover.

Franking is five untagged (hi-bright ink) Circus Wagons (SCOTT 2452B, KRAUSE-MINKUS 1007) and two block tagged Locomotives (KRAUSE-MINKUS 873, SCOTT 2226).