Factory assembly (primer-paint-undercoating) sequence

[astat1]

I am looking for the correct sequence of what was factory assembled on a 70 Hamtramck car, after primer. I do believe that the car was primered, painted, had all brake/fuel lines, fuel tank front/rear suspension (no tires) installed, and then was hit with the undercoating. My questions are:
1) Is this assumption correct?
2) Is there a difference between front/rear undercoating sequence in the front? I ask this because I have seen photos of well documented restored cars with what looks like body color over undercoating in the trunk (interior wheelwell) and front wheelwells.

I have searched multiple forums for this info, and have not found this clearly stated. Thanks

[twodko]

Our unmolested 69 has body color over the undercoating in the trunk.

[Ryan]

The quarters were undercoated before being installed so they will be body color. The rest of the undercoating ( front, rear wheelwells ect..) should not have paint over it.