Hello,
Like you stated, the barrel is a Weimar Era replacement as indicated by the renumbering & Proofmarks. It does not alter the value of your piece ( well, not in my book ). BUT, the condition does !! Even with it's original finish, the scattered pitts do alter the value of this Pre War pistol. You'll notice the Erfurt Proof on the right side of the frame behind the trigger indicating an added hold open...as it was manufactured in 1911 without one. In a convervative manner, I'd state a value close to a good + shooter...in the 600-800 range.
To me, your pistol is a valuable one as it is the first year of Erfurt production. ( I DO NOT have an 1911 in my Erfurt collection !! )
I'd get a correct mag ( wood base, nickle body & double Erfurt proofs ) as soon as possible to complete your piece which I believe is a nice addition to a collection...( until you can upgrade it...but that's another story !! )
Mark <img border="0" title="" alt="[Wink]" src="wink.gif" />