12 x Stainless Steel A2 Hex Set Screw M10x40 with nuts and washers.
Not sure about gaskets.
Suggest you .....he may have gasket and fitting kits available.
If I decided to fit extra bracing I would fix it using 2 x 10mm nut & bolts either side, rather than screws.
I've had screws shear off.
That would be my own personal preference of course!