Old Model Ruger Bearcat. Pre-1963 production as no emblem on grips. Early model with "z" prefix before three digit serial number. Engraved cylinder (not accounted for in book value). very light wear on tip of barrel and line on cylinder. I don't know how it wound up in a Colt box! Dad probably had the extra box and stuck it in there since it fits perfectly. $650 obo.