Actually, a bunch of the Amtrak SDP40F units were traded by Amtrak to ATSF for a similar number of CF7’s and some switchers and the SDP40F’s got front “porches” and were put into general freight service and lasted into the early 2000’s. They were hard to tell from the F45’s at first glance but when you saw the notches in the front cowling to allow crews to walk around the front porch and also noticed the space behind the radiators where the steam generator / HEP generator used to be THEN you could see the differences.