(.Y.)---by "pop the head off", do you mean with the metal pin and all? The helmet comes off easily, but the bushing that the 3 faces are attached to is attached from the top with a pin and to the bottom plate with what looks like a plastic axle that I'm going to regret pushing out. I'll be getting another to check out your theory on them all being this way )I looked around for info on the subject on the site here and nothing came up). If I get a chance this weekend I'll post pictures.
To everyone else, thank you SO much for your wealth of knowledge on the subject