The difference is actually a bit more noticeable, as the Imperial II communications tower definitely had a different design from the Imperial I tractor beam array (on top of the bridge). The other differences between both are probably not even visible. Victory I and Victory II on the other hand, I’m not sure about the visual differences.
Doesn’t the victory 1 have the giant “wings” in an x shape in the side and the victory 2 doesn’t?
Both versions have the atmospheric maneuvering surfaces.
Can they really open up outside of fanart? In all official artworks I’ve seen they look pretty connected and rigid.