DeadHead: “So right before I do the mpeg encoding, would it be worthwhile to switch the sequence (and I suppose each nested sequences) codec to 10 bit apple uncompressed, but leave 720×480 so theres is no positioning changes?”
This would be a total waste of time, your will not gain anything.
However, if you recapture the original video at 8bit or 10bit SDI uncompressed, then rebuild all of the effects and color correction you will have a better end product.
Fred