[DavidG]

Those four holes are to secure a trunk on the rack with bolts through the bottom of the trunk. Other than the non-rack-based Potter trunks for the '33-'34, the last U.S. Ford-released trunk for use on a rack was in the 1932 model year. As the rack portion itself was carried over for the '33 and early '34 models, the '32 trunk fit those racks as well.