honestly, I do not think I have yet to take up a B25 since their introduction to the game........
for the P47, that is the gunsite.....if you was to move your head position over and line up infront of it, you would be able to use it just like you use the iluminated gun site... ( anyone notice the Hamilton decal on the prop? detailed )
same for the D3A, the P40, and sorry my mind escapes me right now.but most planes with a gunsite like that or like the D3A Val are usable in the game, I have used them to see how accurate they are.......