If you implement the Deref trait, for the most part, your &T can act like and be used in the place of &Target.
This is how Box acts is usable like the T it wraps, alongside the other "smart pointers" such as Arc and Rc.
Technically, you should probably have HashRcByLoc<T>: Deref<Target=T> rather than HashRcByLoc<T>: Deref<Target=Rc<T>>, due to the specific semantics of Deref, but any place one type should be used as-if it were another type is a reasonable enough place to impl Deref.
Also consider using shrinkwraprs to automate some of the newtype-forwarding boilerplate.