Construct the fins and inter-fin ‘brackets’ using aluminum plate.

Add bevels to leading and trailing edges of the fins.

Bend the brackets to fit over the airframe with edges that will allow fins to be bolted on. Bending or rolling the brackets to follow the shape of the curved airframe and also add the fin edge interfaces are not trivial without equipment or tools to create these precision shapes.

This type of interlocking construction will be extremely strong and stiff and will also be capable of withstanding high aero heating.

The nature of the material used will not allow for creating complex aerodynamic shapes – simple straight edged bevels.