yes, IG is the EPCOT entrance between England & France.
See what you originally paid for your pass - mine was from 2012. BUT, as has been said, they still might not "bridge" because of the new pricing structure though it is certainly worth a shot (btw, a current 6 day PH, at the highest cost period, is $574.47, which should be the closest comparable pass since the older PHs didn't have any time period restrictions). good luck!
yup
my 6 day PH cost $307.95
in 2012 (from UTC), the pre 10/16/2018 gate price for a 6 day PH was $511.20 - a $203.25 (or 66%) difference