I have this small auto repairs shop and a customer came in with a 1995 Defender 90 that lost the rear mud flap... along with a good chunk of the lower body where it used to mount. Wow. I did a small bracket for a previous job years ago and might reuse the design, but I'm debating if I should rivet straight into the lip again or try a cleaner inside mount with rivnuts. What's the better route?