that part is pretty hard to come by. I fixed mine and then had a friend make one from ABS so I could have a real surface to hold the seal in with. here was mine I used tape and super glue mixed and added baking soda as a filler for the holes so he could get a good shape to make the part from. it took him about 3 weeks to get it right and we used up 1/2 a sheet of 1/8" ABS just test fitting the part. I wish we had taken a molded part off of the replacement piece since My 66 also needs one. it''s in the works again after the engine is finished and as I get the top ready I'll post pic's of the progress. I 'll probably make the mold this time and them make 10 or so since I tend to like the 64-66 darts and valiant convertibles. I have 2 66 darts right now.