Look under some of the GFR sites on the internet. There will be a collection of Grand Funk Railroad posters. That particular show and concert is on a poster and is identified that way by the site.
The historic Grand Trunk Railway no longer exists as such. However, there is a Grand Trunk Corporation, which is a holding company that owns quite a number of other companies, including the Grand Trunk Western Railroad. Please see the link.
The Grand Trunk Western Railroad (reporting mark GTW) is an important subsidiary of the Canadian National Railway (CN), constituting the majority of CN's Chicago Division (itself part of CN's Southern Region).
Grand Canyon Railway was created in 1901.
Grand Junction Railway ended in 1846.
Grand Junction Railway was created in 1833.
Grand Trunk Railway was created in 1852.
Grand Trunk Railway ended in 1923.
Grand Canyon Railway ended in 1942.
Grand Haven Railroad was created in 1878.
Grand Haven Railroad ended in 1881.
Grand Elk Railroad was created in 2009.
Grand Funk Railroad was created in 1968.