Grow 45 re Renfrew
Yes, I believe you may be right, the M8 is alleged to follow the centreline exactly. I remember driving on said motorway in the very early 70s and the old control tower could be seen from the road; the rest of the site to the north becoming a housing estate. On the other side of the motorway, was the Rolls Royce site (Hillington), the buildings of which certainly looked like they belonged at an airfield.