curious parts differences

[Kizilsakal]

I have realized some differences between parts I have
lets see what the experts think

first the fuel door

I am guessing the red one was made up but the grey one is how it is supposed to be. the grey one has a spring and the red has a metal tab acting like a spring also the door itself is made different

and the back window inner brace part

one has braces behind and more holes, what are they for?

 

[Kizilsakal]

bump.

does anyone know why the last parts are different?

also I need the the right hand side of those pieces, I have 2 left hand ones some how. any one know where I can find these?

 

[Stevehose]

the red fuel door is not correct and my rear window pieces don't have those brackets.