Original elements were used to make the SE, the same ones used to make the '77 film (GOUT). That's why their starfields match.

When the ANH crawl was composited in '81(?) they used a different starfield plate than '77, the same they had used for ESB.

Or maybe it was the same plate, only flipped or rotated or something. I'm pretty sure Zion knows the answer, and you might find it with some searches.

I think you'll find the Japanese SC to match all other ANH laserdiscs in that respect.