Are there excess lines in MI, IN, and OH? This might provide a way to connect the SOO to eastern Canada without the NS trackage rights. Based on what he did at CN, I think Harrison's idea is to fill strategic holes in the system.
The NYS&W might give better access to New Jersey, which they already pulled out of, although they would have yards, and access to online businesses. What percentage did Walter Rich retain in the CR split? CP could buy out his estate, or heirs. It could be a joint operation, like Pan Am Southern. If NS and CSX split their holdings 60/40, like the rest of Conrail, CP could, by buying Walter's share, gain the majority.
Iowa Interstate would could give a longer line haul to CP on cars bound to the west on UP and BNSF. How much do they interchange now at Chicago, Clinton ( IC&E), or Ottumwa? I agree IAIS has to be doing well, as they have enough business to acquire the fleet of new locomotives. This line is more strategic than DME, although the ICE part gave a KC gateway.
MMA would be a steal now! I heard the track is poor, but so was the D&H, when they bought it. To make it work, a guarantee with large shippers, like Irving would be needed.