Question on transport is a tough one. Skip the local ATF office, and contact the firearms technical branch in Martinsburg WV. Their phone # is: 304 616-4500.
That is making an assumption (dangerous thing) that your Dad is an 01 Dealer FFL, and that none of the firearms are NFA arms- that is, fully automatic, short barreled rifles, short barreled shotguns, destructive devices, or "any other weapons" (cane guns, shot pistols, etc)
Normally a dealer can receive at his licensed premises, or at a show.
The scenario you give is a first for me. The Tech branch of ATF will give you the straight poop- which a field office agent does not always have.
Good luck- and if there are any older Mossberg 22s in the stock your dad is picking up, please remember the helpful guy you talked with on the forum.
BTW- when transporting firearms- if they are unloaded, and NOT in the passenger compartment of the vehicle, and legal to possess both at the origin of your trip and at the destination, there IS a Federal law known as "Peaceable Journey" that permits that- they are not "concealed weapons" within the meaning of state laws.