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Josh is right, Jerome. This is one a group of ex-CN SD-40's that were purchased by the BNSF and then rebuilt to SD40-2 standards. The cabs were also rebuilt and they have a peculiar boxy look to them. I think the back porch looks longer because of the lack of handrails.
Josh, you're right, it's that double roof that makes it look odd. I thought they had done an external rebuild to the cab but I forgot they came from the Great White North. The BNSF is a great believer in getting the most out of cheap motive power that they can.