If anyone is interested in this, I found that scratchbuilding 40 ' box cars and passenger cars and any other car that is box like in shape can be easily made by using a lego template 2 blocks high and 2 1/2 blocks long...It is perfect height to hold all the sides together at right angles until dry, then add the roof right over top of the lego, making it a mold you might say until you have the roof on, then just slide the box car off the lego and add the floor and trucks, if you have kids, you can grab all their lego, put templates together, cut the walls and ends to size and put them together quickly and easily without having to fight to make the sides and ends perfect 90 degree angles.