Several small variants exist on the different models.

The fourth concerns the screws on parts before behind, underneath.
They are two different types, one to flat print (first one) and the other to cruciform print (last one) :

Green Eagle transporter 1 st release are only with the screws suckled flat.
White Eagle Freighter 1 st release are only with the screws suckled flat.

Green Eagle transporter 2 nd release are only with the screws suckled cruciform.
White Eagle Freighter 2 nd release are only with the screws suckled cruciform.
Blue Eagle Freighter are only with the screws suckled cruciform.

As it is extremely easy to change these screws of an eagle to the other without letting trace, contrary to the exchange of the motor for example, one can find other variations but I think that it is not of origin.