I watched a video of how Porsche prepared the cars on assembly. My interest was in the paint process. In the video, the narrator mentions that the car is not ready for delivery until it get's it's character. Therefore, I'd expect that chassis serial numbers AND engine numbers have nothing to do with the number in a series. The engine, I can tell you, is nothing specific to a Weissach and until the color choices are made and car sprayed, fitted with red piping and other "Weissach" options, the chassis is the same as any other SC.
That's
my view only folks
I have a Black Metallic Weissach and will contribute to the cause by getting the serial number and other info to the various sites.
Tony