Hi - thank you for writing in with the following hallmark question:
" I have a brooch - marked 925 - with 1157 AR - looks like gold over silver"
the brooch could be Italian and AR the province for Arezzo.
Silver gilt or gold over silver is called Vermeil and was popular around the 1700s. You can read about this in an article - date and value tips by sharon here.
In 1956, Tiffany Jewelry revived the process. Gold items marked 925 or sterling are vermiel.
