I've got the OE bar end weights fitted with TT handguards, as I found the vibration with the much lighter TT bar end thingies to be intrusive. A couple of washers fill out the gap, and also prevent such unpleasantness as the throttle sticking wide open.

To be honest, I wish I hadn't bought the TT handguards. I was after weather protection more than crash protection, and I think the KTM handguards described in other threads - which fit with very little in the way of modification - provide better weather protection for a lot less money.