I frequent High Noon Gun Shop in S. Venice. Great staff, indoor range for handguns and rifles up to 5.56, etc. They also have shops in Sarasota and Bradenton, S. Venice is closest. Keep your eyes open for all the Pawn Shops dotting the landscape. They buy up estate sales (a lot of old folks die around here on a regular basis) and with the high population of veterans, retired LEO's, etc. the Pawn brokers are very fertile ground for old stuff like SAA's, S&W, Marlin's, Winchester's etc., just bring your negotiation skills to get the prices down.
Shoot me an e-mail when your in town and if I'm around I can meet you at the S. Venice shop.