In September 1969,General Motors implemented a plan of standardizing the look of GM dealerships.The "Signs Of Leadership" are shown here.In fact the signs you are viewing are 1:25th scale models that were made and distributed around this time.They were often seen on salesmen's' desks.Today they go great with scale model dioramas and promo car collections.They aren't easily found,but I would aim for toy & model shows too.
..also here's an Oldsmobile that just sold for $210.
http://www.ebay.com/itm/Oldsmobile-Deale...=p2047675.l2557