There is no practical way to do a DCS upgrade of that locomotive. You are not going to fit a flywheel in there, and to change the motor to a vertical motor with a flywheel would require replacing the power truck(s). That will require significant mechanical alterations to accommodate the new truck(S).
Again, you are trying to push toothpaste back into the tube, it's simply not worth the effort or expense.
Why are you "committed" to doing the next to impossible?