You might want to look into a long eye relief pistol scope which could be mounted over the center of the bore. If a conventional scope is mounted on the receiver, it needs to be offset so as to permit ejection which is almost straight up. Such installations also require that the safety be replaced. There is a way to modify the safety by grinding, but it really is not very safe, being only held "on" by friction.

I'd be glad to help check the TD numbers, if you wish. Some sites are not very good, and unfortunately one of the worst used to be the SA site itself.