From what I remember, the only difference between the Hasegawa Lightning and the Frog copy of the mould is that the panel lines on the Frog one are a bit chunkier. Subsequent Novo releases have if anything made them worse with age. The F6 that Revell have announced is this kit.
As for Hasegawa's "retool", the only differences were added blisters and gunports on the ventral tank and the cockpit got a floor and a stick.