Since neither your stepfather nor you were aware of this box prior to its "abandonment," I get the impression (from NY Abandoned Property Law section 300(1)(d))that it would have been the bank, not the Comptroller, that sold the safety deposit box contents.

If the proceeds from the sale of this property had already made to the state's unclaimed property list, I don't understand who gave you forms to access the box's contents, or why. It seems that the contents should have been long gone by then.