Take it your talking about the clamp that clamps the clutch assembly to the bars?
I have used helicoils a lot on old bikes before to repair stripped threads. For it to work it is drilled to the next metric size (being metric threads), tapped to the next size up (probably M7 or M8) and the SS insert is put in and locked, then you can use your stock bolt.
Now I have an R3 std and I think it uses a different block to the Touring, and the sad news is I went and had a look at the clamping system and there is not enough meat to be able to drill and tap for the insert to go into, the metal just too thin. Unless the design is substantially different.
Think you need a new block. Just a thought I'm not certain the blocks are unique to Triumph so another brand may be exactly the same, probably easier to get and cheaper.