So to answer some of the questions, the jungle sight does go to 800. And I can take some picks of the markings, but its stamped england with what appears to be a crown. The serial number for the ABL is 367.
Story is I got these from my grandfather years ago. I had his stories on them but over time my memory faded. I was debating selling some but still am not sure. As far as the after market sights, that was grampa. His eyes were going and he still wanted to shoot them.