The Phase One value we obtained for G7's center symbol was "L". The next step is probably to connect that Phase One value to one (or several) of the outer numbers. Here's a shot in the dark:

1. Louisiana is the only American state that starts with an "L"
2. Louisiana was the 18th state to enter the Union.
3. There is an 18 among G7's outer numbers, so 18 is the correct number
4. "R" is the 18th letter of the (English) alphabet.