Just picked up these two EMD builder's photographs off e-bay. Thought I would share for the benefit of all who like detail images.
Keith, Thank you for posting the photographs. It looks like the grab irons on the right hand side of the ends were added by the Frisco after delivery. On the front end (short hood), these were "L" shaped. They were added to help when using the steps to go up or down from the front running board at frame level to the battery box top and cab floor level. The right hand grab iron horizontal was level with the third grab iron on the left and the vertical portion of the "L" extended upward. There was a small bracket at the right hand (elbow) turn in the grab iron. On the rear end (long hood) the grab irons were horizontal only. These were also located horizontal to the third grab iron on the left hand side. Neither the front or rear added hand rails were of the "drop" style like the original. Photographs show these grabs on full stripe and later paint schemes. Therefore, they must have been added early in the units careers. I remember how the step wells on the GP7s were largely square when viewed from above. The side handrails turned down from horizontal at a right angle at the steps. This presented an large open pit as one approached the steps from above and raised safety concerns. In an effort to improve safety and allow for three point contact the extra end grabs were added. On later model locomotives, EMD modified the step wells so they tapered to a more shallow width at each higher step. They also modified the side handrails to turn back on the horizontal at an angle to match the step well before turning down. This helped reduce the possibility of stepping off into a deep void. From the top the side hand rails were also angled to more closely follow the incline angle of the steps similar to the end hand rails. Hope this helps. Thanks! Mark
Another modification made soon after delivery was to cut openings in the sloped sheets above the footboards through which you could drop the ends of the multiple unit (MU) air hoses. Also, unless I am mistaken, I do not have photographs handy, the 27-pin mu receptacles and conduit below them were painted yellow at some point. Gordon