With that style chainguard, I'd say eraly-mid 60s. I don't think anyone's started decoding later AMF numbers. I'd suggest looking at old ads here, at the Cabe, and Nostalgic Net, and see if you can match up the paint scheme/decals to a specific year ad. I know Western Auto was one store that shifted manufacturers constantly. I have two Westfield/Columbia frames with WF badging that look to be mid-late 50s middleweights. Adam