UPDATE:

I solved my problem I think. The pictures above are accurate and the measurements are correct, IF the car has the stock master cylinder on it. I do not know when, but I do not have the stock MC on it. I had to take measurements and get the appropriate amount of extension to fabricate.

Meaning, I found a nice automotive bolt that was M6-1.00 thread and then slowly with a hand file grind away at the head until it was the exact right length protruding form the booster. The result. is NO slop in my brake pedal, and a rock solid and powerful set of brakes. I look forward to moving on to the next project!

Summary:

Pass through plate had all the rust sanded smoothed and POR'ed. I refinished the firewall and then put back the booster and master cylinder. I had to fabricate a bolt to act as a plunger, but when I got it adjusted right for my particular MC I had the best brakes my car has ever had. It feels like a new car.

My advice. Run the tests on your braking system that the FSM suggests. If the brake booster fails, then replace it. Your car will feel like a whole new animal!

You take the word "meticulous" to a whole new level. Good job!

you know Frank, if I can help just one more person, it is worth it. I have been the beneficiary far more times than I have been the helper. I like to do what little I actually can.