If you have a tank large enough, I would park the barreled receiver assembled as recommended above. If your tank is short, go ahead and park normally. You can always run some steel wool over the chamber end...........if you weren't worried about taping the inside of the receiver, I wouldn't worry about the barrel either. If you're using a press, I don't think it would make any difference.
There's a good chance, this gun is already finished. If so, how'd it go?
Matt