Can't forget about my Warrant Officers in the US Army!
If using PLA, I recommend resizing the blocks to 98.5% so it can fit snug/tight without using glue. In my opinion, it just looks better to insert it tightly than to glue it in.
To insert each block inside the space on its designated bar, you'll need a rubber hammer and a very small (watch type) hammer with a wide flat-surfaced center punch. The rubber hammer for the center and the small hammer to seat it properly at each corner. It doesn't take long at all if done right.
Using a SLA/LCD (Resin) printer for this design is highly recommended because it comes out smoother and the blocks inserts nicely without using any hammers or tools.
The author marked this model as their own original creation.