Quote: "I'd like to see a picture looking straight down at the breech area, and a close up of the left side breech area."
I hope these will fill the bill.
EDIT -- It's funny what you might see in a photograph that you missed with the naked eye. There is some possibility that the photo below shows a maker's mark. Looks like it may have been stamped in with either one or two stamps. At the bottom is five diamonds in an X array and above that what appears to be a capital letter "I" although it could also be an "L" with the lower leg obscured. Sorry about photo quality. It is hard to get a good image on the curved surface of the barrel. You can possibly see the diamonds better in the left-side photo.
I hope these will fill the bill.
EDIT -- It's funny what you might see in a photograph that you missed with the naked eye. There is some possibility that the photo below shows a maker's mark. Looks like it may have been stamped in with either one or two stamps. At the bottom is five diamonds in an X array and above that what appears to be a capital letter "I" although it could also be an "L" with the lower leg obscured. Sorry about photo quality. It is hard to get a good image on the curved surface of the barrel. You can possibly see the diamonds better in the left-side photo.