What was the original finish on this particular make and model of pistol? Was it blued? Was it a matte or glossy finish? You can’t tell from it now but does anyone know based on the year, and model?
Typical Finish on Tanfoglio Pistols from it's time frame was a matte Blue.
Not sure that your accuracy test was indicating a worn Barrel, as this was a rushed range session. I would Chronograph some loads to see if there was a substantial velocity loss.
I would also cork the Chamber, put vinegar or solvent in the barrel, and let it soak for a couple of days to remove more carbon. Go easy on the Bore Paste stuff, as it can wear a bore.
If accuracy does not improve and there is substantial velocity loss, the latter indicating a worn throat, by all means, replace that barrel.
Also note that Barrel twist rate for Tanfoglio Pistols of that time frame was 1 turn in 14 inches which favored light 100 to 124 grain Bullets.
Current Barrel Twist Rates are 1 turn in 10 inches or 1 turn in 12 inches, depending upon model.
You may have to contact IFG/Tanfoglio for a Barrel.