Unique tool type/mod help

[PyrotechnicCake]

Hi, so I've managed to successfully mod a weapon into the game before however now I'm wanting to attempt something more ambitious that I couldn't seem to find anywhere else, although I hadn't looked thoroughly. I'm creating a character mod with a friend, and the character herself is nearly completed, but we did want some custom items she could craft, the first one causing me issues is her gravedigging shovel, it's designed to be shovel that can also be used to hammer gravestones. I can make it a shovel and a hammer easily, however I don't want it to be able to hammer other structures and I don't want hammers to be able to destroy graves. If there's a way to make a custom tool type that I could add to the shovel so that I can make it able to hammer graves and only graves that would be ideal. Right now I have it set up so that the gravestone prefab is edited to have it's own loot table and is hammer able, so I'm hoping I can change it and the shovel so that it's a little bit more balanced.