Combines need assistance

If gas cap will go on and tighten up like before, it should not matter if little flap is closed. I think it is more of a anti siphoning device than anything.(keep thiefs out)It is too far removed from gas tank to stop splash out and cap is not vented anyway.Broken off piece is too large to cause problem with fuel pump pickup so I can't see down side to it making it in to tank.Consult dealer for his opinion when you get time but I don't think it's urgent.Filler neck is usually connected to plumbing which connects to tank via rubber hose and is removable.I'm sure it could be removed from car and broken piece extracted.I tend to agree with the guys at the store.I am not a "real" mechanic.I just played one on my own stuff for 30 yrs.Good luck.

You might try a good set of snap ring pliers,slip them inside the piece of noozle and sqeeze and see if it will pull out or maybe screw a lag bolt into it and the threads may bite enough to pull it out.

if the peice is stuck at the top a large tap would probly work well to if you could thread it in there

To get better response, you may want to take a digital photo of it, then post it. Without looking, its hard to give the best advice. I don't know that car'sIJ details - sorry. Or maybe it is something you can not take a photo ofIJ

filler neck is attached to a rubber hose behind rear fender, detach hose, open gas filler door and remove screws, remove gas filling assy from fender from inside of fender, should be able to put in a vice and remove, scott