All CT's were made when they were only doing DHT for the larger knives. That one was probably worked till it was even.
It was much later when they offered a through hardened large knife. But, honesty there isnt much difference in performance. They're all good, no, better. Much better.
EDIT: to add, The first through hardened big rat was the Black and Tan Battle Rat, shortly followed by the Battle Guard. Black blade and tan handle. But no CT, IIRC, was through hardened.
Now its a stretch, but that could, actually not probable, be a black n tan Battle Rat ground down, but I dont think so.