By fall 2020 The Met’s doors are open in a safe and very limited way. As the glamorous, highly-anticipated Costume Institute show “About Time” comes together, museum staff wonders who will pay for new acquisitions, the crucial but very costly research and conservation work, and infrastructure projects vital to the survival of an antique building. Every department is calling in favors to patrons and supporters, from old-money philanthropists who have contributed millions over generations, to leading collectors realizing the time is right to make their private treasures public.