Watch for re-perforation (to fake a more well-centered stamp), for re-gumming (a major problem with the Bank Notes), and even
for bleaching
of the cancellation (to remove the cancel). Unused copies carry a
substantial premium over the used stamp.
We include the "Special" printing, 211D, in this
identification guide merely for completeness. Only 26 copies were
sold, and it was never issued for postal use. We occasionally see uncertified copies
of this stamp offered for sale at ridiculously low prices. You can
rest assured that the stamp being offered is not genuine.