There’s a mold on Etsy, but it’s probably too small for your needs. Try different Google searches, you might be able to find and purchase your own.
https://www.etsy.com/listing/70449112/scales-of-justice-flexible-mold-push?ref=sr_gallery_8&ga_search_type=all&ga_includes0=materials&ga_search_query=resin+mold+polymer+clay&ga_ref=related&ga_page=1&ga_view_type=gallery
If there’s not a bakery near you that can do it, another option might be to do a flat silhouette style piece cut out from chocolate.
Jenniffer White, Cup a Dee Cakes - http://cupadeecakes.blogspot.com
