Are you looking for a website that has drawings showing the locations of the rivets? I use this website that shows the locations of the aircraft's framing and panels. The rivets would be at the panel edges and at the frame members. I also look at photo of airplanes.
https://drawingdatabase.com/north-american-p-51b-mustang/
I don't try to be 100% accurate. I just try to make a reasonable looking representation of the real thing.
