If you look close, you can see that this letterhead for the Cape Cod Saab dealership lists none other than Kurt Vonnegut as the manager. He would eventually drive the dealership into the ground for, among other things, referring to the Saab as “the ultimate yuppie canoe”. Years later, he claimed that the only reason he was passed over for the Nobel Prize in Literature was because the Swedes were still upset over the Saab thing.
Letterheady.com has a whole bunch of fascinating letterheads of great significance, from the historic (early IBM) to the notorious (Adolf Hitler). I really like this one as well: