Using the 35mm grain plate (obviously) boosts the contrast. I intend to pull it back down and use a combination of AverageLuma (in ScriptClip) and "analyze=true" (in RGBAdjust) to verify that my tweak to pull down the boosted contrast results in something that's as close as possible to the HDTVrip source as possible.
I'll post my script-in-progress tonight.