New main springs!!!! They must have been expensive to re make !!!!!!!!! And there's not many people selling them

The rear lens cell should be a one piece unit that you screw in or out to get the pointer in correct focus. Then adjust the front lens assembly as described by Peter.

The rear lens assembly is two lenses screwed together and sometimes the inner lens is loose and needs to be nipped up to the rear lens. Or .... simply the small ( very small) grub screw needs to be nipped up.

It's a simple job to nip up the inner lens by FIRST REMOVING THE POINTER then removing the whole rear lens and prism assembly to access the inner lens.