The large papal medals have always impressed me with their depth and detail. Giuseppe Bianchi produced an engraving of the Basilica at San Giovanni de Laterano on this medal in 1851. While the medal is large at 82mm, the steel stamp used to produce the medal is huge! Basilica of San Giovanni de Laterano https://jumpwhenisay.files.wordpress.com/2012/03/dsc_0558.jpg Steel stamp made in 1851 by Giuseppe Bianchi for the reverse of the medal. Image from History of Rome site http://antiquorum-habet.senato.it/en/
Great medal! It's very interesting to see the reverse die (and its large die crack) as well. Thanks for posting!
Out of curiosity I dug out images of several examples of this medal to see if they exhibited die cracks (I couldn't see any but cracks can start out quite faint.) A uniface striking that went unsold in a recent ARC auction had pronounced cracks from the cracked die.
The medal is a much darker brown that the seller's images. At 264 grams and 9mm thick, it must have required a great deal of pressure and/or multiple strikes to bring up the details.