Surely I'm not the only one trying to work with some pretty crappy engineering drawings and trying to design stuff to fit on those machines when they are on the other side of the world.
You know the thing, all the customer has is a fax of a fax, and photo of a drawing, or what seems to be getting more for some reason, a photo of someones CAD screen!

So then you have an image, the straight lines are a bit curved, the parallels aren't parallel. Its a jpeg or a ping or a pdf or some image file, or distorted hard copy you have to scan (though that's getting pretty rare). There is a selection of features with dimensions on, but not all of the ones you need so some attempt at scaling is required.

Who has what techniques for dealing with this and perhaps getting a usable dxf from it?

Are there any working software packages for straightening out the distortions?

There it is on someones cad screen, so wheres my dxf? well dont ask, that's all politics and legal stuff.

Some examples heavily cropped to protect the guilty