vikki, you asked:
> Is the C451B noted for being a bright mic?
Definitely. The original C 451 wasn't neutral-sounding, either, but it didn't have nearly as much treble emphasis as the C 451 B has.
If your audio editing software has an "equalizer" feature, you might want to try reducing the energy in the area of 2 - 4 - 6 kHz a few dB to see whether that brings you closer to reality. You may well find that you can make significant improvements with even a modest amount of EQ, and that you don't need to change microphones.
By the way, you may not get much benefit from the advice you were given to aim the microphone away from the sound source. What you will mainly get that way is a reduction in proximity effect (the bass/mid-bass boost which directional microphones give at close range), and of course you'll pick up more room sound.
--best regards