Thanks bro, that's helpful. I just carefully checked this one, and I'm seeing dead-on 5/16 (possibly a hair's thickness under that, but that would be it, if at all).
So it appears the one I have here is a Chinese pin, as advertised, so it's this BulletButton/Prince50 front sight apparatus that seems to have an out-of-spec hole in it. Supposedly, these were made to have original Chinese parts installed. I messaged the guy (Prince50) over on the other SKS forum, asking for advice/info, or even to get the new barrel that the upgraded version now comes with, but haven't heard back.
Thanks again for getting back to me......