The TNG First Year Sourcebook has a somewhat more accurate drawing of the Constellation, if still not perfect, this time having the nacelles in the right configuration and noting how elements of the studio model are more flattened and some of the saucer hangars. It also has a much more accurate depiction of the warbird, with the tail added in and some of the vent details visible on the wings.
Constellation (OM version)
Constellation (TNG Y1 version)
Warbird (OM version, Type A?). It's interesting to note that Starfleet had only limited intelligence on the Romulans and new ship classes due to their isolation, and didn't know when the warbird class first entered service. The B type is mentioned as the first major upgrade, and it's fun to imagine the Enterprise-C could have fought a group of Type As at Narenda III. Maybe the tail was part of the hull variation?

Constellation (OM version)

Constellation (TNG Y1 version)

Warbird (OM version, Type A?). It's interesting to note that Starfleet had only limited intelligence on the Romulans and new ship classes due to their isolation, and didn't know when the warbird class first entered service. The B type is mentioned as the first major upgrade, and it's fun to imagine the Enterprise-C could have fought a group of Type As at Narenda III. Maybe the tail was part of the hull variation?
