There isn't any KM reference in the Spain, Portugal and the New World reference book, however, you can reference the actual photo of this in the 1988/1984 issue of Calico &Trigo's Numismatica Espanola. This is being offered to those cob researchers of cob related fakes of which there are many. The item "4R 1590 Granada Silver Colonial cob" is in sale since Tuesday, December 7, 2021. This item is in the category "Coins & Paper Money\Coins\ World\Europe\Spain".The seller is "joedaddycool" and is located in Berlin, Connecticut. This item can be shipped to United States.