Updated 7/5/2018:
Made some serious progress yesterday and today. I cut 3.5” lengthwise off a table that was too wide and moved that up against the uprights for the divider. That piece will hold a track that enters and exits the Staging Area, allowing empties to be exchanged for loads (and vice versa). I made the appropriate changes to the track plan to allow for this modification.
I also cut a notch in surface No. 5 and fit it into place. This involved making two parallel cuts and then using a drill and keyhole saw to complete the hole. I then squared up the hole with a Dremel cut-off wheel and grinding tool.
I placed the order for the rest of the lumber today as well.
Pretty good progress, if I do say so myself. 
George
