Rust repairn filler neck

Have a 93 Ford E-150 I use for towing boat and camper.
Filler neck has rusted at support clamp. RockAuto, Napa, Adavance etc do not stock a replacment.

Have not checked the dealer, will do tomorrow but looking for a source or repair advice.

After I clean off the rust what epoxy if any will work to seal it from leaking gas?

There is some stuff that will supposedly fix holes in gas tanks. I would think it would work for what you need. However, if it was me I'd replace the neck.