I recall, several years ago now, a graphic in an issue of Simithsonian Air & Space magazine that illustrated how, between the end of WW2 and present, a dozen or more major aerospace firms merged into the the two major outfits (Boeing and Lockheed) that exist today. I’m wondering if anyone has an extensive back-issue collection who could point me to the issue in which this graphic appeared, or could point me to an online resource that describes this progression?