Yup... About 2.5" added. But the good news is that in the event of a "make things right" scenario, that would not be a difficult fix. The line of the old tang is still very visable. So the extention may just be soft soldered in place. There would have been worse off and harder to correct ways of adding that tang.
Here is a photo of an extended tang on a back action that I own.
image.jpg
I would not stress about photos of the bores. It is very hard to get good pictures of bores and even then, they may not tell much. Physical description is usually just fine.
Threaded Mode