I will be putting a Nine Lives Racing wing on my SLC. I plan on adding a mount to the rear clam 90 degree hinges after I reinforce the welds. They are made from 1/4 plate and are the perfect width for this application. My question is what are they made from. The superlite parts catalog list them a laser cut from steel. They are magnetic (ferrous?) but look like stainless steel. In the four years of driving the car (some times in the rain) they have no rust not even at the pivot points. I need to weld a bracket on them but want to match the metallurgy. Fran?