Actually I missed page 5 with the video before my last post. Functions just like mine. Thanks.

I have in my possession 3 hammer pins, my original, plus two others from GPC (original broken, GPC 1 too short, 2 too rough to use). None have any mark depicting a right or left end as shown in your video AND all are perfectly symmetrical in all dimensions. On these three examples of the hammer pin I cannot find anything that determines a unique orientation for the pin.

The only issue with my gun and its hook is the elongation of the keyway. Why the elongation? Perhaps poor workmanship at the start. A monday morning filer after a heavy night with the grogg. Or, perhaps some long ago 'gunsmith' had trouble fitting the pin back in and decided a little more slop was 'just the ticket'.