My Street Demon install experience

So I got the tank and sending unit ready to install. The last 6 to 8" of the fuel filler neck that protrudes into the tank was kinda krusty so I sanded, filed, and got as much of the crud off as I could. My question is....

Should I replace the fuel filler neck too or just clean it up and call it a day?

If replace, who has the filler neck for a 71 Dart Swinger with the 4 vent line tank?