I just noticed this thread so I'm a bit late in replying.

My 110 FCP HS recoil lug is not exactly like the lug on my other Savages. The bottom of the lug has been cut in a rectangular shape. Also there is no dimple (key) to fit the notch in the action. Not sure why Savage left off the dimple as like you say the action is notched for it.

However its not very different and I can't (from looking) see why a regular recoil lug with a dimple could not be swapped in.