Hard to say what all the differences are, partly due to the different paint schemes and not knowing what is hidden underneath the paint or not.
But:
Prop
Upper intake.
Lower intake.
Frame behind pilot inside canopy.
Cowl size.
Cowl shape? (dunno if you consider that a "difference")
Engines are different as well as the casing/shield connecting it to the prop.
That nub in front of the canopy is different.
Exhaust port is different.
Some black spot on the wing that I don't see on the earlier model, but, I don't know if this is due to a difference in the paint. Also a black spot/port above the wing root that I don't see in the later model. But, the later model has the black paint there so I can't tell if it has it.
Early model has a leading edge wing light that the later model doesn't have.
Anyways, that was the 5 minute tour of what I saw. I assume, since you are the boss of the project, that you will enlighten us to the rest? Gotta go to sleep!