Did you look closely at that top rib near the breechfaces?
The fair colored line, looks like it might be the solder or brazing of the ribs, seems a bit funny.
Could just be was from them having shined it up for the photo, but it looks like a serewed up rib solder joint, in that photo it even looks like the chamber is ring bulged.

go figure.
I'd hesitate on that until I got to hold it and see with my own eyes.

--Tinker