I agree that the Winchester tang to tang bolt is just fine, if properly installed with a tapered tang bolt and tapered hole. Sometimes these are converted to though bolt attachment that I don't see as any improvement. That fat forend is also something from the 50's~60's that I find unattractive and unecessary. High and Low Wall Winchester rifles were always my favorite projects.
A nephew of R.Southgate showed up recently on the Longrifle forum with some info.