Coarse Scale is something of a misnomer. O gauge models were built to a range of standards with the toy-like products of Hornby, Mettoy early Marklin, Bing and others. Wereas Bassett-Lowke Leeds Model Company and Milbro worked to a more prototypical standard.

O Gauge was Common in the 1920-1950 but is much less so these days with most modellers electing to go for the smaller scales. The exception to this is, of course, the Collectors  of older trains and some of the new products by ACE  ETS Lionel and others who build models to a very high standard but their running gear is to Standard Scale enabling them to run on a wide range of track work that the ultra-fine models will not tolerate.  

The "Hornby Railway Collectors Association of Australia  is well known for this side of the hobby  and a link to their web site is in the links page The following Gallery pages and videos illustrate this aspect of the Hobby