multiple models flight sim (help)

I need some advice on how to design the next version of my game. I have created a flight sim and i would like to now add support for multiple aircraft. the problem is that the orignal game the scripting and logic is built around the orignal aircraft model. if i want to support multiple planes should i duplicate the scenes and coe for each aircraft ? or dynamically load the model at runtime. if i load the model at runtime how do i define the position of lights? currently i have created point lights in unity and placed on the model how would i adjust these lights to a different model? how do support the movement of flaps etc for multiple aircraft?

 

Create a prefab for each aircraft and make all variables witch are different for each model in the script public and save the different settings with the plain in the prefab.
Its a lot better because if you find a error you do not have to fix 10 scenes or 10 scripts you only can change it once.