The other day a CBP -60A came through the airport at work. I went over and peeked in it and the cockpit looked more like a Bravo or Foxtrot cockpit with the addition of the TDFMs, MTS, and what looked to be an upgraded NAV select panel. But what was interesting to see was the 530s jammed into the dash to the left and right of each AI/BDHI.
I remember back to a NARG and hearing the integration is too complex. Hard and expensive, certainly, but not impossible. See also: HF in Romeo.
And for the record, it's still weird not seeing a C-Power switch on the collective.