LDO - I'll try it in words, hard to get good pics - there are rivets at each end of the vent frame that hold it to the channel, one at the very top top, 2 at bottom - those go under the felt and from your description will be the ones that are loose .... there are 4 rivets that hold the rubber vent seal, head ends in the 4 holes under the felt, crush ends sunk into the holes in the rubber [which has a metal core] .... there are 2 rivets that hold the sheet metal trim piece to the main channel, they go head end in [through] the felt, crush end under the rubber .... so there are 9 holes in the division bar, the "raised bosses" you see are rivet heads, probably the ones that hold the frame and the trim
Bill
