Well one of the original Harkness’ Hulthemia hybrids, Nigel Hawthorne, is a cross between R. persica and a rugosa hybrid. It looks like a lovely shrub, but as long as I know it is completely (or virtually) sterile. Anyhow, going back to the original species would be really difficult; what would make more sense to me would be crossing modern hulthemias with a rugosa, or possibly a fertile modern-rugosa hybrid.
The rugosa-modern hybrid way is not easy at all (health+infertility), but I don’t see why using a modern hulthemia would be different from using any other modern shrub (+ the fact that you would need way more seedlings than usual if you want to get some good blotches). The main problem will probably be going on to the newt generation, due to low fertility level.
If you decide to try it, please keep us updated, it should be really interesting!