Hi Tom, the old Galvanized steel of yesterday is not the same as today.
We used Galvanized wrought iron and Yalloy besides “galvanized steel”
Today with all the chemicals to improve water quality you may want to get a pH reading before installing any materials to find which may hold up the longest.
It is not so much as external corrosion your now worried about its also internal.
Nevertheless after 30 years I would think about a new service pipe is in order.