Had it been an English gun as there is a gap between the tubes at the muzzle I would assume that the barrel has been shortened .But there is a fitted stop piece in the bottom but not the top so the question is has the top stop or plug come out and the ends just filled with solder ? I do not know how Fox ribs were finished i.e. did the ribs have a fitted end or were the ends just plugged with shaped pieces ?
As you have rejected the gun the question is now academic .