Ok, the hex head size was what I was thinking. After looking, the bolts on my door were 5/16-18 (vent window to door inside door) and 1/4-20 (external lower vent window to door and all door latches, handles, etc.). Sorry, I don't have any extra bolts that held the channel inside the door. The upper channel (flexible) and the top of the vent window was a #6 bolt (if it was loose, I used a #8 to secure).
I hope that this helps a little bit. I just put my doors together within the last month. If you need any other door bolt size, just ask.
FYI, this was on a 51 3100.
Chris
