Chinese Cannon Of The Forts Of Shan-Hai-Kuan

Here are some images of Pocher's 1/20 scale Chinese Cannon Of The Forts Of Shan-Hai-Kuan.
One would think that when Pocher produced this kit that they would have supplied some historical information on the subject at hand but alas no.
Web searches on this subject were so far unsuccessful.
Update - I've been told by avid model cannon collector Matthew that" the Chinese cannon was captured by Italian marines during boxer rebellion circa 1900 or so." Have a look at his fantastic site https://www.flickr.com/photos/110082008@N08/sets/72157638489604955/