Ok, I have the distributor disassembled. I have the exact same number on the advance plate as the one in the article that Crackedback posted. I will be welding those slots as described.
Now as for the spring kit I just happened to have one of them. It says that if I use both of the springs in the kit full advance will be at 1200rpm.
Do I want to use 1 or both springs? How should I set that up?