After an examination of the roster list I checked on the history of the CN painted GTW 5938 that is shown as a choice.
CN 5171 became KCS 6620 then became GTW 5938
Perhaps it could be offered in the original CN scheme and number, plus the KCS scheme and number, to get the most out of the distinct variation.
GTW 5937 or GTW 5936 should have been a choice as well.
Andrew