I found a Japanese Youtube that shows this post but it calls it Record, which I am close to 100% sure is wrong.

It's some early MTB post (late '80s?), but not Euclid, not Record OR, but cheaper. You can see the line where the head has been pressed into a piece of tube, which is how many longer (especially MTB) posts are made. Record of course was machined from a one-piece forging, not tubing. Also this post in question has noticeably cheaper/rougher machining, so it's not a top-end offering.

There was a two-bolt Euclid similar to this, but nicer finish quality, so I'm pretty sure it's not Euclid. Most Campy MTB posts were one-bolt designs similar to 1-bolt Super Record.