Probably a different light but I recall one on what I think were then English Electric Offices. It flashed green and was the visual identification beacon. Wasn't used after around the sixties I think.
Midland operated Dublin from the late sixties and the routes to Glasgow via Leeds and EMA briefly in the early 70s- the via Leeds route was I think then operated by Dan Air 748s again fairly briefly. A variety of aircraft were used on the CI route including Heralds,F27s and on occasion Short 360s London City Dash 7s.