We’ve been around, just very behind and short-staffed (no excuse, I know), and we wanted to do some research. Thanks as always for linking us in to the thread. That being said, this first response will be just about the Fusible Links themselves.
We have always, and only, sold the genuine factory Nissan fusible links.
The 0.3 link was 24161-N4200, and superceded to 24161-Y0100. No service files show on these numbers. The originals we used to receive decades ago (as far as us “old guys” seem to remember anyway) were Brown. Then, many years ago, Nissan started sending Red links under that same part number. Relatively recently, the Red links were discontinued from Nissan for a time, and then a short while later, they made them available again, but this time what was sent for the same part number was Brown again, not Red. We unfortunately did mess up as far as our listing still recently showing Red (even though we were sending Brown). It was just an oversight where my department neglected to follow up and change “Red” back to “Brown” on the website. But they were always what Nissan was supplying for said part number.
The 0.5 Green link was always 24161-28500, and the 1.25 Black link was always 24161-A0100. There are no supercessions or service files on these specifically (only the 1976 bulletin where they changed to 4 links, as you guys noted). So the 1975 listing was just an embarrassing mistake/unfortunate informational record typo that blossomed (AGAIN by MY department, sheesh. I’ll make sure there are floggings). It has now been fixed to where it should have been, with 74-75 being the “same”, not 75-76 being the “same”. Again, thanks for pointing this out.
As far as the position of the 1.25 link on 77-78, we absolutely did take the positioning we showed directly from Nissan’s documentation, and are conferring with them and our own archived data about the error. I will be going today or tomorrow to access our stored 1978, and will respond to that part soon if there is anything worth adding to the discussion, since you guys have pretty much nailed it all down already.