Regarding the different fits with shirting:
From what I own I would say that 1950's fit a little bit boxier than 1940's. But what about First Shirt, Six Shirt, Classic Shirt?
Maybe Six shirt > 1950 > 1940 > Classic > First Shirt
From SS14 collection
Our classic chino style pant. Straight leg with a slight taper toward the ankle. Waistband curtain on the interior, horn button closures and zip fly. Exterior label with removable overlock stitch at back. Constructed with up to 2" to let out or taken in in the seat or waistband to allow for easy tailoring. Shown here in a soft, relaxed and lightweight pre-washed cotton.