ORA-1 ratings are sort of like looking at an ORR-Ez certificate through a pinhole. You can only access a small segment of the potential ratings.
That said, there is not a full-blown ORR-Ez certificate "behind" every ORA-1 certificate, but the boat data is there and the process to "upgrade" to an ORR-Ez cert is fairly simple.
To clarify, there is not really a product called an "ORA-1 cert"; it is a GYA PHRF certificate, provided by Tom Beery. It was designed to meet his specifications.