66 Coronet can't stop it

My 66 Coronet wagon has never had good brakes from the time I bought it. So with new shoes, new booster (extremely rusty), new master cylinder, I now have almost no brakes, and still very little pedal. I've had some fairly capable Mopar shadetree mechanics circle it and test mechanical functions. Even after my daughter put new (a little softer) pads on, we still got nothing. The pedal stays close to the floor with a 1/2 inch of movement which is hard and fruitless. (It doesn't pump up for any pedal, either.) I, a rookie at this, installed the new brake booster and master cylinder and it has been bled more than once. So maybe I did something wrong, or maybe the new booster doesn't work? Now I've been advised to just go manual or buy another booster (and hope it works). I have the required plate for a manual transition (but not the rest), but either I'm tired of this two-year old problem, or just need some solid advice. My hope is to ready it for sale. It is very original, and I've already got $2400 into it, so I'm not looking at high performance brakes. I'll save that for the 69 Dart I've just bought. So advice, suggestions?

It's not the booster causeing the problem. Most likely the drums are worn down too far or the master you installed is bad right out of the box or you have a leak somewhere in the system. I thought I had a bad master on my 69 Dually, but I found a rusted out line. You might want to check and make sure the rod that goes into the back of the master is adjusted correctly as well.