For primary material on specific aircraft, the strongest sources are the manufacturers' own documents: general-arrangement drawings, maintenance manuals, and structural repair manuals, many of which survive in national archives and museum libraries. Institutions such as the Smithsonian National Air and Space Museum and the Royal Air Force Museum maintain archives and collections that include technical drawings, period photographs, and preserved airframes available for study.
For the artwork side, the journals and exhibition catalogs of organizations like the Guild of Aviation Artists and the American Society of Aviation Artists document the genre's development since the 1970s. Scale-modeling society publications remain one of the best places to see line drawings debated and corrected in public. Whatever the source, the working rule from the main page applies: match details to the exact variant and production block, and prefer claims that can be checked against more than one independent reference.