Those things are just thin sheet metal and are in place to prevent roof flex. They are not structural and don't touch the roof, contact is made through dollops of seam sealer. If you have a brace made up out of sheet metal and have it make contact in a similar way it will work just the same. OEM is nice to have but it's not necessary if you can't find one.

 

agreed 100%, it would be easy to make one out of aluminum if you wanted to save weight vs the stocker. Im running a Marsh Composites roof and was searching for that brace for the past year. Im happy to say that its absolutely fine and very rigid without a brace and im not even gonna bother making one at this point.

 

I have an intact roof section that I bought to harvest this exact part, I'm not sure when I'll need it so if anyone is interested in having some made I have a part to model after.