Well... that was just awful! As easy as it was to assemble all of the individual loads, applying the straps was a true PITA. I used thin black tape which has an adhesive on the back but the strips are so thin that the adhesive wasn't much help. The straps still had to be held in place until the ACC dried. And it just seemed like it would never end. After I finished the first row, it became obvious that I was never going to get through two loads this time around. So I punted and only completed one of them. But alas, one of them is done- see below.
As I was working to complete the load, I struggled with how I was going to make it removable. Last night, I looked through the folder I have with old flatcar articles in it and the solution was in the very first article. Bob Rivard, who's work I have long admired, did an article in the January 2014 issue of the NMRA Magazine titled "Modeling Canadian Pacific Flatcars." Bob used a trio of Proto 2000 flatcar kits for his article, and he described in detail how he made the lumber loads. In order to make the loads removable, he took four pieces of 2x6 basswood, cut them to the width of the deck, and then inserted pins made of wire to hold them in place. He then glued the load to these pieces. It's a brilliant solution, and I copied his technique. The only difference is I used two pieces of 2x6 instead of the four he used.
For appearance sake, I may go back and two more. And the load really does need some additional blocking in order to be prototypically correct. I may yet try and figure out how to do that as well, but for now, I'm declaring this project finished- finally!!!