I agree, there's something not quite right in that area - the curve of the cantrail seems to start too far up the bodysides and/or is far too sharp. The cantrail grille towards the no2 end of the loco should have a gentle curve throughout. On the CAD its got a sharp 'kink' in the middle. The cabside windows and the cab door windows look too deep - easy to spot if you look at how they relate to the bottoms on the windscreens on the real thing. The rain strips should drop towards the ends of the loco but they appear horizontal on the CAD - that in turn will affect the position of the cab side windows. The rain strips also determine the correct shape and position of the windscreens. If you fudge things up in those areas it then makes livery application a bit awkward. Somehow there is not enough space between the rain strip and the top of the bodyside louvres - it suggests the tops of the louvres are too high up the bodyside (are they too tall perhaps), along with the windows, as a result of the cantrail/roof curve being wrong. The the 50s tumblehome doesn't seem prominent enough on the CAD , and neither does the ledge below the windscreens. It still looks a little flat fronted like the old Farish one
I'm not sure I like the look of the CAD at all I'm afraid - and that's before even thinking about how you'd then get a stripey livery - NSE for example, to sit on the model correctly if everything on the bodyside is in the wrong place.
Jon