wow, you´re doing some pretty cool stuff!
for the double layer print i the black layer printed with “deep-black” (that ink with the bigger pigmets) either as a first layer before printing colors or as print on the back of the transparent foil. I know from some guys here in germany that they do it like this but they do not want to tell me who does it for them… afraid of ebayers I guess.
as an alternative I could also imagine to have 2 prints. one with the full MSD (black and color) and a second one only that deep black without any colors as kind of a mask layer.
I don´t care about the gels to have it authentic that would be like building a tricorder with crappy printouts and without sound because the original prop was silent