Yeah, at least its plugged upstream of where the front & rear split apart. Since it's diagonal circuits, it would be a nice coincidence for both caliper bleed screws to plug up at the same time.

Up from the caliper(s)/wheel cyl is the proportion valve???? Again, just me but the OP states the brake pedal goes to the floor.

OP- Start the car, push the brake pedal and hold pressure on it. Does it sink to the floor?