So, forward with the hardware swap, some nice steps made there.
This is the ABS 5.3 unit still in the car;
Then, taken out (along with bulkhead feedthrough block as I need one with the additional rear line)
And the ABS 5.7 in the car (not screwed down, so it is still tilted a bit)
I also managed to take the single rear brake line and the T-union out of my car and replaced with the two rear lines from the wreck (along with union). Front brake lines mounted back as well.
It does seem like I will need to swap out the rear brake lines, or at least the right rear (which is the hard one). The nut on the brake line has a different thread than my old brake line. I removed these rear lines from the wreck as well today, but install will have to wait till the work on the front side of the car is done.
Next step is to finalize the two brake lines to the rear (tighten them, clip them in) so I can re-mount the washer bottle and headlight etc. Then I'll finish the front left side of the car with a new brake hose and the S-brake (disc and caliper).