You know I think you should do it little bit other way:
Bf 109 - models - E1, E4, F1, F4, G2 , G6, G10, G14, K4
Spitfire - I, Va, Vb, XI, X, XIV, XV.
etc... you have too many models of same aircrafts
for exemple even 262 had
262A1a, A2a (with 2 canons and 2x250kg bombs), B1a, B2a (night fighters)
So if you contincue to do it this way the list will be veeeery long


for idea - final list of all WW2 planes - (not it would be implemented in close future - but anuway good thing)