Here is another 4 layer reverse engineering PCB project.

                                                         TOP with components

                                               TOP without components

                                            TOP without components and solder mask

                                                 TOP from SVG drawn by me.

                         TOP with components from SVG drawn by me.

Inner layer 1 .The glass textolite between the top and inner layer 1 has not yet been completely removed.

The glass textolite between the layers is thin and becomes almost transparent.

I have milled away part of the traces on Inner layer 1.

There is always such a risk - that's why you should scan slightly before reaching the inner layer.

                                      Inner layer 1 from SVG drawn by me.

Inner layer 2 .The glass textolite between the BOT and inner layer 2 has not yet been completely removed.

The glass textolite between the layers is thin and becomes almost transparent.

I have milled away part of the traces on Inner layer 2.

There is always such a risk - that's why you should scan slightly before reaching the inner layer.

                                    Inner layer 2 from SVG drawn by me. 

                                                    BOT with components.

                                 BOT without components and with solder mask.

                                     BOT without components and solder mask

                                           BOT from SVG drawn by me

                          BOT with components from SVG drawn by me.

In the attached file you can find svg with Vias , Top , Inner 1 and BOT layers.

Inner 2 has been deleted by me.

It's possible that I have made mistakes somewhere - everything is drawn by hand on the pictures from the scanned layers!