I don't know if this could be a 70mm/35mm visual-difference as there was many unfinished shots in the earlier trailers, but this fx sequence in the original theatrical trailer is a little different from the finished film.

Trailer footage above with the same frame on GOUT footage below:

As you can see, the two snowspeeders was composited into the scene much earlier in the trailer-footage and they don't have any laser blasts animated to them. I don't have Puggo's super-8 version to check against, it's probably just an unfinished shot but it could be worth checking.