This model is from the very earliest launch in 1956. It is the Rover 90 with a friction motor, probably the least popular of the early models.
The 204M Mechanical model was usually produced with this solid fairly dark shade of green as well as a scarcer metallic finish.
The paintwork on this one is all original but not in very good condition, with plenty signs of playwear. The motor works well, however, which is nice after all these years. The windows are also mostly clean and clear and the silver paintwork is pretty good although there is not a great deal of it! (I have just noticed that I need to clean the front window and others are still wet in the photos - they are all free of scratches and cracks, though.)
A genuine original example of a quite hard-to-find edition.