That Lock 45 is amazing! It's the reason I gave up knife collecting. I wanted one so badly but none came for sale at any price. So I decided to keep my collection in stasis. I still have about ten knives I love, but I sold off most and haven't bought any more. Because I'll never be able to find one at any price so there's not really a point to keep trying to collect for me. Maybe that's weird, but it's how I felt a several years ago and the feeling hasn't changed.
I only know of three, the one in the OP's collection that he posted a few years ago, one in Sal from Spyderco, and one in the hands of a South African knife maker who knew Chris. When the hunt becomes impossible, it's exhausting and time to move on to new endeavors in life. I still like looking at other people's knife collections but I'm likely retired from the game.