Need some help. Were on vacation so I don’t have access to any of my reference books. I visited a pawn shop this morning and found a 6 1/2” Single Six with a 501xxx serial #. According to the Ruger website this would be a 1968 Magnum model. There were no indication on the frame, barrel or cylinder that it was a magnum. I looked at the box and the model number is RSSM and the serial number on the box matches the gun. It has been fired but is in 95%+ condition. It has a barely visible turn line. I've got a '56 Flatgate and a couple of '58 Single Sixes but have no experience with magnums. Is it normal for the RSSM to not be marked with magnum and should it have a LR cylinder? It's marked $450. Being a pawn shop I know this is negotiable. What would be the top price for one of these? Since I'm out of state there will be $30 shipping plus a $20 transfer fee at my local FFL.