Did you get a complete windshield frame? I bought the brackets like you but used the horizontal straps and hardware from a Roadking windshield I got for free. The quick detatch bushings are not part of the windshield, they are part of the motorcycle. Go to
http://partsfinder.onlinemicrofiche....=13&A=288&B=37 and it is part #19 you need 4 of. You could also get washer #5 (8ea) or use your own. Ignore the side brackets in the picture, you have the correct ones.
I wouldn't cut up the Fat Bob windshield, it is too valuable and could fetch $150-$200 easy on this forums classifieds or eBay. The Memphis Shades plastic I got is the 19 inch (pretty tall and I am 6'3"). It was also cheaper to have my local H-D dealer order the FLSTC replacement with Ruby tint than to purchase it online. It was $87 plus tax versus the same or more with $20+ for shipping. This is a superior windshield to stock.