Here are pictures of revolver with the Lyman Ivory Bar rear sights. The first picture is the left side of the gun. It has a pair of ivory stocks.
The next picture is the right side of the revolver.
The next picture is the left grip, showing the initials ever-so-lightly engraved.
The next picture is a rear view of the ivory bar adjustable rear sight. The factory letter refers to these sights as Lyman Ivory Bar.
The next picture is a top view of the rear sights.
The last picture is the Lyman ivory bead front sight blade.
Regards, Mike Priwer