Okay, this turned out to be the project from the underworld. The tube method worked fine, all created without a snafu.
First problem...there are four squares and I alternated the center designs...one of the squares WASN'T alternated. Did I notice before I put on the border? No. Removed the offending square and reconstructed.
Second Problem...wonky border. I had a wide yellow and a thin green. (If I had had to deal with this problem in the past I would have quit quilting!) Decided to remove the green and work with the yellow. Better, still not best.
Third Problem....I chose a decorative quilting stitch that I really like. The problem was that it caused some puckering (user error) that impacted the backing material.
Fourth Problem....Because of the puckering, the backing isn't square at the corners and I have HAD IT with this project.
While I love the colors....and love the tube method....I could kick myself for how badly I completed this.
It is now gracing the top of my front-load washer where only I can see it!