Brie, absolutely great pieces is all I can say. Congrats again, wish I had them.
Sorry I have not had time to get back to you on these but it is the silly season after all and time is short on the best of days.
As a few people here already know, these B1's popped up in Japan fairly recently and do appear to be legit original laser disc posters from what I have seen although I did not make the connection when they first started selling myself. There have been roughly about 8-12 or so to come up for sale there that I am aware of in various condition from Good to NM, all rolled and from the same seller if memory serves. The two things to look for on the B1 is the size and the coloring as it does not appear to be the same as video release posters in color only but it is definitely a B1 size obviously.
I have not had time to sit down and revisit the images from hepcatpunk but based on the HA auction when it was live, I did look then, the size is spot on for the B1 but the coloring once again is off. The coloring though is again almost 100% guaranteed to be off due to color/saturation effects employed by Ha. If you color correct to more realistic levels in photoshop, it will almost certainly match up. All things considered I think they are again likely the laser disc video posters which I think are rarer than the score SWMP gives them but worth that much? I don't think so. I would be a buyer myself at maybe half that price.