The ridge is only there for safety as I said.
The little bracket is only there to stop the shock turning.
The shock is held in place by the clamping force of the 12mm bolt
Have a look at all other shocks how they are mounted...exactly the same, except as most are not used on tracks, they don't have the 'safety ring' to stop the shock getting punched through.
As I said I have seen an Escort Cossy where the shock 'punched through' and fucked the tyre as it hit the spring cup!!!
Cool calander by the way...THANKS