I can't recall that I've ever seen such a thing myself, even with all the crazy scripting tricks out there. I mean, even I could turn an armorer's hammer into a weapon in the game, but it wouldn't be useful for repairing damage anymore, just dealing it.
I just thought of this as I typed this up, but I do suppose one could create and attach a script to a hammer that fits under the category of "Repair Item" in the CS, and whenever the player picks it up, the script gives them the option of using it as a weapon instead, kind of like the scripted Dwemer leggings option in that Dwemer Armor replacer mod I used to use.
Any other input/suggestions/corrections are welcome.