I am a newbie, planning to purchase an old model Single Six, serial no. Old model ruger single six for sale, old model ruger single six with serial number starting with 43, ruger single six, ruger single six action revolvers serial # look up, ruger single six forum, ruger single six identification, ruger single six old model, ruger single six serial number lookup, ruger single six serial number starts with 60, ruger single six serial numbers.The barrel appears to be 61/2' and on top it reads STURM, RUGER & CO., INC. SINGLE-SIX with the Ruger logo and an R inside a circle. The right side under the cylinder the serial number is 21-40515.