Built and installed a new extended supply plenum, added wooden supports. Built and installed new T shapen return plenum, reusing a Honeywell 20x25 media filter and added one additional. Removed satellite box feeding the master bedroom, replaced with 8x6x6 metal wye and homeran the other 8 and 4 inch flex to the supply plenum. Reconnected all existing flex to the new plenums. Sealed all ductwork connections with mastic/hardcast. Tested heating and cooling operation. Everything is working at completion of service.