Note that even though full annealing will not take place raising the temp of a hardened part will draw or temper the hardness. Raising a case hardened part to 750-800F will definitely temper out the "File Hardness" it obtained on quench.
Personally I would not see this as a problem on the top lever, but is a definite reason for not "Torch Coloring" frames. Likewise I would personally not want a double frame which was originally case hardened, even if I were willing to switch to a blue color ,done by any method which exceeded 300F.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra