1956. There may be a Cw after the 56 on the number. It's an AMF made bike, just after CWC went to Arkansas. It has that great configuration of the old Roadmaster frames. Made for cruising.
That bike was built not long after Shelby and CWC were bought out by AMF. It has a leftover Shelby chain ring and that tank Should fit some model Shelbys as well. The fenders will most likely be leftover CWC's. Most of these end up in pieces.