I also thought he was asking about just the stock. Can't say I've ever seen one for sale. If the whole gun in really great condition is in the $600 range I'd GUESS someone would pay at least $100 for an original stock.
It actually was a complete rifle but the serial number fell outside the range of what I thought were possible manufacture dates. I don't know if only stocks were ever offered for sale by Ruger and if so, how long they might have been available.