Your stamp with a relatively minor shift and being used might be worth a couple of dollars if you could find a buyer.
Likely would sell for less than the cost of selling it, if sold by itself.
As to rogdcam's eBay example, $75 is quite wishful thinking for an item well under $25 in knowledgeable EFO circles.
While The King
is quite popular this was one of the larger issues in modern times with over half a billion, 500,000,000++, made.