This is, IMO, not going to be an easy or cheap fix. I have multiple S&W 745’s and as previously mentioned one has the same issue as the OP although, after looking at it again instead of from memory, its not nearly as pronounced as that pictured by the OP. I did a barrel swap among my 745’s for the sake of interest.
The 745 is not a 1911 and most likely doesn’t need/have the hand fitting as a 1911 yet like the OP’s 1911 it’s a production gun. The barrel swap made very little difference, actually it made it slightly worse by perhaps less than 0.002”, a difference of 0.001 probably wouldn’t be noticeable.
My guess is having the barrel replaced and/or having it refitted is not going to correct the visual issue. Assuming there are no other issues I would compare the Sig 1911 with an identical model before a decision is made to make any changes to the metal.