Hello
Know that may be tiresome but I try cover all this aircraft's which aren't in polish OOB because were small and not strict military. I don't expect that you found all icons usefully I start to paint them because such activity have fun factor like model building as you mentioned that. Use that what may be usefully for game and simple left the rest they are just propositions.
But still I imagine some scenario for example with Romanian RWD-13 medical evacuation but that will require some hardcoded addition and new class like Landing Aircraft.
RWD-13 may land like now in game code gilder but with different sound of engine and without variation in place of landing just simple land on airfield in exact place. Then player must lead infantry as cover unit and valuable unit with wounded soldiers to aircraft. When wounded are loaded for example we my have in the same place were now hovering button for helicopter a launch button and in next turn our aircraft simple lift out and go out map so made a reverse trip of gilder. I know that such functionality need a change in game code but will be great to have such missions as air landing attack where Ju52 land on airfields and solders instead of using parachute just simple go out from aircraft or evacuate that way from airfield.