The one you have looks like it came from this site: http://fjperformanceinc.com/index.php?main_page=product_info&cPath=433_438_486&products_id=1013View attachment 246306 View attachment 246304
This one is metal that I got off of eBay. It's made for a Pontiac I think. It physically fits perfect. The numbers were way off compared to the Buick stock tab so I grinded them off and lined up zero and center punched it. Then I sanded and shot it with clear.
ATR use to sell a timing doctor sticker to put on the balancer. Someone was reproducing these and selling on eBay. It originally went all around the balancer but I cut mine where the critical spots are.