Just a quick note. In Swinyard’s note I see a reference to dimensions: 24′-0″ long x 7′-6″ wide and 6′-6″ (inside) tall. He also notes that the cars were really being built 6″ narrower and was quite disturbed by the decision of the car shops to sheath the cars with the sheathing horizontal instead of vertically. In his original survey he quotes a quantity of over fifty cars and later over one hundred and twenty. There’s no mention of any other freight car types though he does not that some boxcar decks were being used by the contractors as makeshift flat cars. If I remember correctly there are some great photographs of the Charlottetown and Summerside yards that I could look at to see if any other car types appear.
I am going to put together a quick drawing for one of these boxcars over the weekend. I have some really drawings of D&H and CPR box cars that I may turn to for some framing sizes. Once I’ve got that main drawing done I think I’ll try and tweak it a little to work with On30.