Didn’t the Bluray restore certain elements that were “fixed” in earlier releases such as the WOWOW? I’m talking about things like the matte lines around the sea-plane. If so then it would be better to use the Bluray as the source for a regrade.
Yes, certain changes were reversed for the bluray, but other things were changed in stead, like adding a light above Indy and Marion when the arc was opened. On the whole the WOWOW has more detail, and less black crush, and blown out whites, so the WOWOW is the better candidate for a regrade. However, since we have both available, I will go for the best of both worlds. In principle the WOWOW will be the main source, but I will use the bluray for those scenes that had been digitally altered to create the master used for the WOWOW.