Please note that I haven't shown nothing at all for this is not my video and I haven't made anything of it.
The question of how the cutted end of the pin is "locked" remains open as far as my understanding goes. Therefore I am happy that you are willing to discuss that.
So, you suggest that it is brazed (which may not work with chromed pins)?
I feel like I should be able to braze the cutted end of the pin to nothing more that the closest part of the hinges. The part of the hinges are very thin so they should store very little heat, making it easy to control which one would suck the solder - maybe?
That would be certainly more informative to ask directly as a comment to the video, for those who own a Google account.
Thank you very much for your interest, anyway!