This revolver is lot #2573 at Morphy's April 2019 auction:

https://auctions.morphyauctions.com/AGIANT577_BLAND_PRYSE_5_SHOT_REVOLVER-LOT464533.aspx

There were probably less than a hundred of these Pryde-Patent break-action .577 revolvers made in total, and this one has managed to maintain an excellent nickel finish. Pushing approximately a 400 grain bullet at about 725 fps, these 5-shot revolvers were made as last-ditch “stopping” guns in case of attack by large animals, and most of them were taken to India during the Victorian period. This one was made in Belgium, and then retailed by Thomas Wilson in London.

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