Need Advice on '65 Barracuda Brakes...

So, it pulls hard to the right... Started the Bleed Process. No Fluid to Rear, at All.
Okay, I'm thinking Collapsed Line from the Frame to the Rear End. Moving On...
No Brakes on Drivers Front, Opened it up and it's Soaked with Fluid.
No Problem, Two New Wheel Cylinders for the Front, (Napa here I come)
at this point I'd be happy with just the front working til the next round...
So, thinking everything is in order, I start to bleed the new front cyl's...
Now, No Fluid to the right side that was previously working but the drivers side is now fine?
Pedal does Not go down when you bleed the rear or the right side.
So did I collapse lines or do I have a Prop Valve problem?
Can the P Valve really stop the fluid from getting to the two different places at once?
Where do I start from this point?

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