On later superform wings the upper mount bracket is secured with six flush mount rivets in the area of the sidelight mounting. I would imagine slightly forward of bracket, shown looking from behind, to place it at highest point on wing. It could be this area is already reinforced.

[Linked Image]

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone