Hi Mark, OK
To me part of the fun of the hobby is make it as close as possible to what I recall it was real.

This is my plan: Im buying the DVD from Skymaster 707. Then I will use my movie editor to extract the sounds, in mp3, and cut them in parts equel to the same time-length as the files in CS707-300. Then I will convert those files to wav.

Im not going to do it with every sound. For example, Im not touching gear sound, engine starters, flap, door, etc...but I will change wind, idle power, take-off power, thrust general, etc.

Wonder if it will give a better result? Im not sure how to modify sound.cfg to make the sound to a higher pitch, etc. I will only modify the wav files keeping the same sound.cfg and check the result. :)