Curious as to what you are seeing. The only sound files that are in there are R22 prefixed, they have been edited and not the R22 original wav files.
If you use explorer and click on the r22_rpm1_motor.wav to play it, it is a piston engine. The same wav file in the R22 sound folder is very different.
I just downloaded the piston kit and checked the sound folder, and it is the one I am using in the FlySimware Bell, and there are no Bell47 references or files in there outside of extb47.wav and intb47.wav. Folder looks like this:
The only other mod I have made is to the panel.cfg to add the blade slap sound.