I am working on a similar pattern with the center four patch measuring 3/4". I did the strip piecing thing, lined it up and dotted it with Elmer's school glue secured with pins and let it dry. Viola! Ready to start the piecing around it and it has worked fine. The block I am working on is 3" finished so I had to devise a way to do it and I didn't figure anything else would work for me.