They are 7mm scale-ish as they used an Atlas F9 as the basis of the body.
Ted Freemans decals once again make them look better.
While I admire your courage in making them in that scale and most probably a lot of work as well I think your placement and size of the NSW crest plate on the front door is in error. Here is a photo from the front cover of of a Train Hobby book on them. The plate is smaller and higher up on the nose. Not nit picking at all just pointing this out on a otherwise excellent pair of locomotives.