This is a great video from 1999 on how the area used to look. Have a look at how the roads have changed over the years. Dumbarton, Helensburgh and the surrounding areas starts around 1 hour 16 minutes.

Cross Keys on the way out of Helensburgh used to be a crossroads. Loch Lomond Shores in Balloch had not been built. The mini-roundabout and houses by Dumbarton Castle had not been built are just a few changes.