Most likely a BA one, as none of the US carriers on the route had one.
They were often rotated round by the day dependent on cargo loads on different routes.
The ones leased from MEA originally dated from 1975, having been delivered there just as the lengthy civil war broke out. They were leased out to various carriers for lengthy (as BA here - 5 years 1985-90) terms until the 1990s, when they finally reverted to their owner's services.
BA's own handful dated from 1987, so the whole lot were in service in the late 1980s. They were sold off around the turn of the century, a notably short period for BA 747s to be in the fleet.