The 'new' 45 is now out of production, but there are still plenty to be had in shops and elsewhere.
I don't understand why the last version of the '45 has the big hole in its' cap. Is it to reduce the force needed to open or close it (i.e. because there is no vacum under the cap)? I saw someone else call it a "breather hole". I'd be gratefull if someone could explain what that is, or why it is needed?
BTW, no I don't like the jewel either, and I can see why some dislike the new clip, though personally I agree with whoever said in another topic that it looks sturdier and less prone to catching.