Weeelllll, while the idea appeals to me for no other reason than wanting to see a 28 on the hill, the C&TS would come out on the losing end of such a deal.
Why? The 28 would be an orphan. No spares, little in common with the C&TS fleet.
C&TS would exchange a loco with half again as much tractive effort for a less capable loco.
These are, however, just my opinions.