I've only owned one Beretta SXS (471) but I've always been interested by the numerous models offered. You may want to try contacting Ken Pendleton. He's a dealer that "specializes" in older, lesser known Berettas.

His inventory is listed online. http://www.gunsinternational.com/Pendleton-Firearms-guns-for-sale.cfm?show_account_listings=3770

Good luck!

Adam