Use MPGStreamclip to transcode the MPG-1.
Export as 8b Uncompress or Prores to avoid picture degradation.
Keep the same size, pixels, fps.
The audio PCM 48Khz.
In FC conform the sequence to the clips.
Rafael,thanks for the tip. what would you set your "Pixel Aspect Ratio" & "Field Dominance"? I tried Prorez 422. What happens is while the clip is playing in FCP its darker color and when i press stop it lightens around three stops. (looks like shit) any advice?