Hey Motomagz,
Sorry for the late reply, I missed your post. I continually struggle with my fender mounts. The front fender is pretty solid with a bolt going into the bottom of my fork stem, the bottom brace with four bolts in the fender, and my leaf spring fork dampening a lot of the road vibration. The rear fender has proved problematic, the bicycle fender braces are just too thin and continually break at the axle. There is just a lot more vibration and stress on the rear braces. I have never had an accident because I braze a 1/8" thick strap onto the front of the fender and it's then bolted with a lock nut at the chainstay junction.
I have not been able to source a thicker fender brace, so when I switch my bike back to cruiser mode with the larger rear fender, I'm going to try brazing a strap to the axle mounting end of the fender brace in order to strengthen it.
Thanks for the interest,
Gilbert