Here's an article that describes the H1 rims a bit...
http://www.flashoffroad.com/features/Wheels/Wheels.htm
Looks like the H1's factory
one-piece wheels are hub-centric too...but the hub is larger than the H2's so you'd need the ring to run them hub-centric on the H2.
The H1's two-piece wheels must be the ones that were lug-centric...