Road sign being on the right sticks out. I suppose it's there because there's no space on the left but it's nonetheless an unexpected quirk.
NZR liked having ballast blocks on its Pacifics for whatever reason. Keeping with your "It isn't quite Colorado" theme, those ballast blocks could (at a glance) almost be mistaken for the pilot deck toolboxes that could commonly be seen on D&RG power at various times. The A's were built with nice looking flat-side tenders that causes me to like that class better than the more-numerous Ab, but it was very small for a locomotive of that size. Range would've been comparable to or barely better than some tank engine classes. It was eventually enlarged somewhat, but not by a whole lot.