Brake Problem/Warning Light Update with more info

[twilightcall]

I went out this morning to check some items that were recommended to check. As most of you know my brake warning light has been on and my pedal was going to the floor. I changed the Master Cylinder and bled the brakes. Now the pedal it up halfway and stops ok but the pedal has too much free travel and the warning light is still on. I pulled the line to the booster and plugged it off. The brakes were much harder to stop, I had to practically stand on them to get them to stop but the Pedal started to resist all of the way from the top. However it was much harder to stop the car.
I then removed my brake warning light switch from the Proportion valve. I checked the switch and my warning would go on and off according to whether the switch was in or out so the switch works fine. I did notice in the proportion valve that when the switch is in that it is always going to be in the brake warning light on position. I read about centering the valve but I couldn't get it to budge. Shouldn't this valve go down to make the light go off and mine is all the way up and I couldn't get it to go down. Here is a picture of what it looks like. My car is an 83'. Thanks Again for everyones help. I couldn't do it without all of you.

[PKRWUD]

Check your other post.