Hello,
I was quite busy recently but I planned to post a comment to show you the little things to fix before I can validate it 😃

But quickly:

• You have quite a few parts not aligned properly (not snapped)
• The left hand side door is all shifted by 1.29mm
• The back engine (black pieces) is not snapped correctly and I think that parts 3937 are inverted (180 deg.)
• You could subdivide the flexible tube to add a point in the center in order to avoid them going through the 1X1 plate holder.
• Part collisions e.g side windscreen colliding with the roof.

I can help you if you wish.

Regarding the missing part, I don't have this set and therefore I cannot draw the decoration. I you have the set or find a high res photo of it, it would make that possible.

I could use some help.