I have updated the backgrounds for Silvama's great updates for Fenway versions 1934-1939, 1940-1956, 1957-1969 & 1970-1987. Basically, I just removed buildings as the parks regressed in time. Therefore, all this version do not have the same backgrounds.
They are available here:
http://www.mediafire.com/folder/akd2ejkdtk4dx/Historic