BEA had a fleet of BAC One-Eleven 500s built for their German routes (G-AVMH-Z).
Doubt if they were built purely for the IGS routes. They were used on other routes as well, eg Glasgow-Manchester-Paris (or was it Glasgow-Birmingham-Paris? - memory not quite perfect!).
What they did have, though, was a greatly toned down version of the BEA colour scheme at the time as they were operated on the IGS routes in conjuction with Air France so the BEA titling was VERY small and no speedjack on the tail.