Up an Down Operator:
I think your mixing up things.
THRCLB1/ THRCLB2/THRCLB are obviously Auto Thrust related Modes. Left column on the FMA.
Don't know why you are writing about OP CLB and V/S Mode, as they are Vertical Functions of the Autopilot? 2nd column f.l.t.r on the FMA.
Those Modes weren't part of the question posted by "Check Airman"