Went to the local hardware store to buy lumber and hardware.  Very busy today, as Michigan just went into pandemic lockdown.  I think all the folks that were just "furloughed" decided that if they were stuck at home, they might as well do a home project.

Picked up the lumber and hardware in our minivan.  Minivans are designed to be able to hold a 4x8 sheet of plywood if the seats are out, so no worries.  The big-box hardware store has everything you need for this project except holds.  Alex ordered a hold kit online as well as T-nuts, as they are cheaper in bulk that way.