I am not sure exactly what you need to do, but I wonder if you even need an external cloning function. If all you really need is to clone one level deep, perhaps you could just implement exactly what you need in plain perl?

dclone is wonderful if you really want to clone a complex data structure. Last I checked it can deal with nearly anything, including cycles, which normally would be more challenging to deal with on your own. That is the beauty of Storable, you need not worry how complex or cyclic your data structure is, it all Just Works. It just seems a bit much to go through all this work if all you need is the first level cloned.