IIRC, I used 3/8" x 1" stainless bolts with lock nuts and washers for the LOWER fasteners. (7 each side, 14 total)
Couldn't find substitutes for the 20 upper "T" retainers so I reused them. Copy and paste the link below and search, they may have direct replacements.
http://www.clipsandfasteners.com/Clips_Moulding_s/76.htm