Reducing Noise but keeping the sharpness ... ?

I have NTSC 720x480 interlaced footage and I want to convert it into MP4 progressive 640x480.

The original footage is not the best quality but the converted footage is coming out more grainy (noisey) than the original. Its kept the sharpness to a decent degree but it noisey.

What is the best approach in Compressor you've found to getting rid of the noise but keeping the sharpness?

I'm using:

MP4, Best setting, 4500 bit rate

BEST, BEST

I tired adaptive details etc but no improvement...