Ross Mk 2 *** rear sight question

I own a Ross Mk2 that was purchased by the US. When the rear sight is raised, the sight can be adjusted for windage and elevation, and the peep sight is used. My question is, what is the notch for that is directly above the opening used for the peep sight. The peep sight in the photo is set for 300 yards. Is the notch above the peep now set for 700 yards as indicated by the < on the sight?

I believe that the fixed notch at the top of the sight is for max elevation.

Thanks for looking at this.

Attachment 134768

The notch visible when the sight is folded down is the "battle sight"; not sure what range it is calibrated for, but it's the trajectory of Mk.VI ball, not Mk.VII.

The circled notch would I think be read from the line indicated from the left hand arrow, and the aperture would be read from the mark indicated by the right hand arrow.

Looks like someone has been prying under the lower end of the leaf and I'd guess that was done when the elevation screw was turned too far down and some pressure needed to be applied to get the leaf to pick up the thread again.

The ".22" stamped at the top suggests the sight was mounted on a .22 training rifle at some point?