And its not even a problem you only have with older blueprints. The Audi SQ5 I modeled (but never finished) also had blueprints which were not matching from the different views. And additionally to that, I did the same mistake as you did with your Aston.
I just had a bunch of reference images and realized very soon, that I have no idea what an Audi SQ5 really looks like
For the Volvo I now collected 136 reference Images. What I found also very useful, especially with older cars, are restauration blogs where you can find close up pictures of the different parts.
That wireframe Image above makes me think about how you approach getting to the basic shape of the car. It looks very dense, like you already have a subdiv modifier applied? Can you tell me briefly about your workflow?
I normally start vertex by vertx tracing the basic shape and then add faces inbetween.
And do you cut out the doors with the boolean operation, and clean the topology up afterwards, or do you plan it in advance?
Sorry for asking so many questions
Ja servas, ein Münchner, ist ja fast um die Ecke.