In the chart, each block is wider than it is tall, but single crochet is just about the same width and height per stitch. So you need to find some stitch that works up to be the same proportion as the blocks in the chart.
Perhaps you could turn the chart 90 degrees and try working half double crochets and see if you get the right proportion.
Interesting project. I'll be very interested to see what others suggest and how it turns out.