the front bracket on my aluminium valance failed on one side.
The bonding agent looked like a yellow / brown epoxy. I made up one new bracket as one had stress cracked & fallen off coming back from Brooklands.
The other one fell off when refitting the valance, so I figured the fixing method was poor & might fail again.
I stuck both down with Gorilla Glue epoxy (half the price of Wickes at Tesco by the way). I left them to dry overnight with car luggage elastic holding the valance hard onto the brackets.
Next day I used a glass fibre repair kit to strengthen the fixing building up layers of resin & glass matting to spread the area holding the bracket on.
Comparison to RichardV6s Wolff Performance valance showed a far wider bracket held on not by epoxy but by rivets. An altoghter stronger solution.
So far so good after 300 miles. I would guess your is similar.