Marty my reference to Thunderslots is — in the case when and if they are somehow Not readily available. My point is to consider that alternative now, in advance, and be ready when and if that situation ever occurs.
Regarding the size, certainly that was the intent to stick to the Supergrips that when mounted are 10mm wide (as with SIPT28/F30s).
"... get on your bad motor scooter and ride!"
Sammy with Montrose