Yes, the TR posted by Pi22 is the recommended method of calculating the GAI. The other method was a statistical approximation developed by third parties before Pearson released the official method, which was derived from the actual standardization sample.

The FSIQ
Excellent scores one way or the other. Did he have any 19s among the subtest scores? If there were at least two, that would be reason to look into extended IQ scores.

...pronounced like the long vowel and first letter of the alphabet...