I have never seen one of these guns with other than a blue or color case hardened frame. However, I have talked with one collector who says he has one. I have found several deviations from factory catalogs that I believe to be factory original. So...the gun could be original, but whether or not it is, the condition is what determines the value. If the gun is in good condition overall....no rust....excellent bore....wood not badly cracked or damaged or stock cut....and with matching assembly numbers, then the price would be ok. Can you post some pictures? I hope this helps some. Good luck on your hunt!