1970 Dart Filler Neck Replacement/Restoration? Need Help

I have a 70 340 Dart Swinger that will need a reconditioned, replacement reproduction gas tank filler neck.

I can't locate one without the emissions system. Does anyone know where I can find one or have a solution? The tank, lines and motor are new. I don't want to risk using a corroded filler neck and contaminate the fuel. You can't get up in there to clean it properly.....

Thank you in advance