Rivet removal...The factory installed rivets hot and sometimes they seem as if they are welded to the frames. I always grind the rivet flat on top and center punch the center of the rivet. Then I use a 1/4 drill bit and drill through the rivet. This will help give the rivet room to compress when you use a punch to remove it from the frame. The nice thing about surgically removing the rivets this way is that if you need to reinstall the part you can use those rivet holes to rebolt the crossmember or other parts back using 3/8 bolts. Your project looks great. I really enjoy looking at the transformation...Keep up the quality of workmanship.