To add to John Becker's post, Greg Shoults "found" a post card in a dealers dollar box with what appeared to be a coil. The dealer said he though it was faked. Greg bought it, had it expertized and sold it at auction. A good friend of mine was the buyer; I've not had to opportunity to see it in person yet, but will eventually. It certified as a one-cent Franklin from the 1902-03 series and is a Parkhurst Private Vending Machine issue/use. To my knowledge, its the only 314V and Parkhurst certified on a cover/card. It sold at the Harmer-Schau auction at the APS show in Portland, Ore. last year.
Also, in 2015 I picked-up a #544 on a post card off of
ebay; not as impressive, but still a good find.
Just a couple of examples; if you know what you're looking at, there may still be some good material available to be found. Knowledge is the key to finding it.
