lIf you really want to fix it , MEK really never had any luck with a permanent fix. I use SEM Dual Mix Multi-Purpose Panel Adhesive # 39747 . Yes it needs a special gun to use it, you won't be disappointed as it is the BEST repair. JB Weld isn't the same. Wal Mart has it the cheapest but must order it.
Here are my results at grille repair and the materials I used: http://www.v8buick.com/index.php?threads/my-70-gs-grille-repair.314950/
Not doubting other repairs , SEM 39747 repairs hard plastics as SMC panels on Corvettes and fiberglass and be purchased thur Wal Mart just under $40 and won't get brittle or crack later on . Its awesome !!!
Break up bits of scrap plastic and put it in a small paint bottle with some acetone. The acetone will melt the plastic. Get it to the consistency of milk or a little thicker. If the break is super clean, you can just brush on the acetone to both sides of the break. The acetone will melt both sides and fuse it together. If not, use the plastic and acetone mix. It will fill in any open areas of the break. I make a bead of it on the backside of the break to reinforce it. Once the acetone solvents out, the repair is as strong as the surrounding plastic. If you have stripped plastic threads, apply the acetone and plastic "glue" to the threads. Once dry, run a tap through the boss- new threads.
