Here’s an early 1990s pic of IC #6740, a former BN SD40-2.
http://www.locophotos.com/PhotoDetails.php?PhotoID=116559
Judging by the oxide-red covering on top of the long hood, it looks like IC #6740 used to have dynamic brakes. I guess IC removed it since all BN SD40-2s had dynamic brakes. I find it interesting IC continued to remove dynamic brakes from acquired EMDs into the early 90s, even though by that time all brand-new production EMD and GE freight locos had dynamic brakes. I guess IC didn’t utilize locos with dynamic brakes until they bought brand-new spartan-cab SD70s in the mid 1990s.