The extractor plate is supposed to snap back into position when the regular Krag extractor (on the bolt) hits the trip pin on the left side of the action.

I have never had this one apart.  I have seen a drawing (Brophy?).  It looks as if it might be just a parts replacement job, but you would need the correct parts.  I think the springs and pins on both sides are identical, so finding replacements is not completely impossible.  I think it is just a small coil spring and a pin or screw with threads at the small end.

The bore on the rifle I have been using is also VG.  Just 2 small pits near the breech.  I am considering making my own 22 ammo for this rifle.  I just need to spring for a custom bullet mould.  I already have primed cases.

The trigger pull on the rifle I have been shooting is terrible!