Seeing as it has the small ventral tank, it is Airfix (an F1a). You could convert it to F1 by removing the external cable conduits (the two ridges fore to aft on the lower fuselage) and not fitting the IFR probe.
You could convert it to F2 by fitting an intake scoop on the spine.
For an F3 you would have to fit the intake scoop, larger fin and extend the cable conduits fore to just past the missile pylons.
I’m personally doing a 1:48 F1 (my first real attempt in nigh twenty years)
I’m not sure if I’ll use AFDS markings or try and scratch some 33 MU markings.
I’ll be giving it the tail no XM135. Probably one of the more famous F1’s.

thx for the quick insight in the Lightning marks Robert!

regards

Bert