You might want to try a local glass/window shop. We decided to let them take care of Hamlet's Jalousies (panes missing, etc) and they had all the pieces necessary to get them back to like-new condition.
It basically looks exactly the same as the Jalousie top header seal (flat piece with a T shaped top which runs along a channel) I mentioned earlier but is 1/2 (or a 1/4, I'm not near my measurement papers anymore, but I can doublecheck) instead of 7/8ths.
This is all I could find. It is not an exact match. You could call Pelland or email them for more info, mainly for the size of the T. www.rvwindow.com/4.html The Hehr Mullion Seal is about half way down the page.
The other suggestion would be the cut down the VTS Header Seal, provided that the T slides into the slot.
Sorry I couldn't be more help.
Last Edit: Apr 8, 2012 6:58:45 GMT -5 by dawgpound