gngoatに問い合わせていたところ、以下のような回答を頂きました。塗装は、グレートノーザン鉄道が実施した試験塗装を概ね再現するようですが、ボックスカー自体は、流用品で正確さに欠けるようです。ボックスカーに詳しくないので、今一歩意味が不明ですが、屋根（本来は対角線型、アサーンは四角パネル）、エンド（本来は改良型ドレッドノート、アサーンは初期型）、ドア（本来は改良型、アサーンは初期型）等が、違っているようです。
下記の原文は、Staffan Ehnbom氏の投稿です。写真は文中に出ている18007です。
The Models are 40' all steel, but everything else is different. Roofs are rectangular panel (GN: diagonal), ends are 4/5 early dreadnaught (GN: improved dreadnaught), the Youngstown doors are early (GN: improved).Only the 18007 has a correct (Superior) door, which seems to show that they care to the small extent that they do have something that is correct. The side sill shape of the double door cars is different. And the single door cars are twelve panel cars best modeled by the Intermountain car.
下記の原文は、Staffan Ehnbom氏の投稿です。写真は文中に出ている18007です。
The Models are 40' all steel, but everything else is different. Roofs are rectangular panel (GN: diagonal), ends are 4/5 early dreadnaught (GN: improved dreadnaught), the Youngstown doors are early (GN: improved).Only the 18007 has a correct (Superior) door, which seems to show that they care to the small extent that they do have something that is correct. The side sill shape of the double door cars is different. And the single door cars are twelve panel cars best modeled by the Intermountain car.