Yes I got mine fixed. I bought a new blend door from Rock Auto Parts for about $9.63. I cut a hole in the bottom of plenum to remove old door. I drilled a 3/4" hole with holesaw to lift out the door.(dimple in molded plenum that held old door)
I then used a 1/2" copper cap to a 3/4" long piece of copper pipe and soldered it to a 9" piece which I screwed to the bottom of the plenum.

The copper cap holds the bottom of the door in position as the piece of plastic I drilled out. If you want to talk by phone PM me with your # and I will explain in more detail.