I have uploaded the files to the library.
[UPDATE] http://railworksamerica.com/FileLibrary/TS2012/2012/RollingStock-July-2012.html#roinuj-CN_SD60F_Pack.

They are based on prototypical examples of the numbered locomotive with weathering details.
CN 5522 in Zebra Scheme Link to prototype photo.

CN 5526 in Zebra Scheme Link to prototype photo.

CN 5537 in CN North American Scheme Link to prototype photo.

CN 5546 in Zebra Scheme Link to prototype photo.

CN 5560 in CN.ca Scheme Link to prototype photo.
