old thread?? not sure i can help, but i have done the same repair with the same kit and had the same results! that should count for something. I had a couple of "junk" dash pads and decided to experiment. i filled the crack with epoxy and tryed to lay it in as smooth as possible. i sanded and refilled and it started to look good!!!! the texture is the problem. my '66 cutlass has the innie texture and your '69 cutlass may have the outy texture. you can buy rough texture paint in a rattle can and carfully texture the area. i'm thinking you may have to color dye (paint) the whole dash. i've seen this done and it works!
i did the repairs 3 years ago and stored the dash pads in my attic extreme heat and below zerro again tonite and the repairs seem fine!! the repairs look so good that these 2 dash pads look better than the "good" one
PS i also experimented with "super glue" on the little cracks they are still holding also!!