I'm matching colors to the Angrysun rip for now (with Black Input levels calibrated so the letterbox bars are black), first by waveform then calibrating by eye. I also re-color the LD cuts when necessary to match the corrected Blu-ray footage. When a better source comes along I'll match to that.
On that note, what's the opinion on the NTSC LD's colors versus the PAL LD?