I found an old 1981 Lego brochure which contained an image of the Lego 722 Advanced Basic Set with an example of a model bus.
This inspired me to try an old school Lego bus based very loosely on the 722 concept with the constraints of not using any really modern fancy brick elements. I call it a homage to 1980's Lego:
I conclude that trying to make models using brick elements from 30 years ago is challenging because of the constraint on styling - everything looks so chunky and blocky. However, it can be also quite pleasing to try and re-create that Lego feel of my childhood.