More 303 questions

Here are three more odd 303 rounds I acquired recently that have me wondering just what the heck I have. The first looks like a standard CN MkVII with just R L for a headstamp.

It almost looks like the lower third was blackened but I’m not sure. The second round is another E C *II headstamped round this one with a hollow point bullet CN with what looks like black plastic in the hollow.

This third round has an overstrike of the headstamp a circle midway from the rim and primer it is loaded with a fine gray powder and the base of the bullet is marked with an O for Royal Labs and looks to be of standard MkVI dimensions but with the bullet seated lower than it would be with a MkVI. Overstamped headstamp is B C II.